Knowledge

Euclidean space

Source 📝

4084: 3621: 4173: 4079:{\displaystyle {\begin{aligned}|BC|^{2}&={\overrightarrow {BC}}\cdot {\overrightarrow {BC}}{\vphantom {\frac {(}{}}}\\&={\Bigl (}{\overrightarrow {BA}}+{\overrightarrow {AC}}{\Bigr )}\cdot {\Bigl (}{\overrightarrow {BA}}+{\overrightarrow {AC}}{\Bigr )}\\&={\overrightarrow {BA}}\cdot {\overrightarrow {BA}}+{\overrightarrow {AC}}\cdot {\overrightarrow {AC}}-2{\overrightarrow {AB}}\cdot {\overrightarrow {AC}}\\&={\overrightarrow {AB}}\cdot {\overrightarrow {AB}}+{\overrightarrow {AC}}\cdot {\overrightarrow {AC}}\\&=|AB|^{2}+|AC|^{2}.\end{aligned}}} 8670: 31: 8190:, many sorts of spaces have been considered, about which one can do geometric reasoning in the same way as with Euclidean spaces. In general, they share some properties with Euclidean spaces, but may also have properties that could appear as rather strange. Some of these spaces use Euclidean geometry for their definition, or can be modeled as subspaces of a Euclidean space of higher dimension. When such a space is defined by geometrical 8153: 5798: 9412: 4599: 6986: 4458: 8462:, which are the "shortest paths" between two points. This allows defining distances, which are measured along geodesics, and angles between geodesics, which are the angle of their tangents in the tangent space at their intersection. So, Riemannian manifolds behave locally like a Euclidean space that has been bent. 2177: 644: 5957:, coordinates may sometimes be defined as the limit of coordinates of neighbour points, but these coordinates may be not uniquely defined, and may be not continuous in the neighborhood of the point. For example, for the spherical coordinate system, the longitude is not defined at the pole, and on the 8011:
has proved that all these definitions of a Euclidean space are equivalent. It is rather easy to prove that all definitions of Euclidean spaces satisfy Hilbert's axioms, and that those involving real numbers (including the above given definition) are equivalent. The difficult part of Artin's proof is
2713: 169:
has been shown to be equivalent to the axiomatic definition. It is this definition that is more commonly used in modern mathematics, and detailed in this article. In all definitions, Euclidean spaces consist of points, which are defined only by the properties that they must have for forming a
7148: 6834: 371:
allowed their use in defining Euclidean spaces with a purely algebraic definition. This new definition has been shown to be equivalent to the classical definition in terms of geometric axioms. It is this algebraic definition that is now most often used for introducing Euclidean spaces.
2428: 2024: 1455: 6615:
It follows from the preceding results that an isometry of Euclidean spaces maps lines to lines, and, more generally Euclidean subspaces to Euclidean subspaces of the same dimension, and that the restriction of the isometry on these subspaces are isometries of these subspaces.
7936:'s one. In reality, Euclid did not define formally the space, because it was thought as a description of the physical world that exists independently of human mind. The need of a formal definition appeared only at the end of 19th century, with the introduction of 3369:
Two lines, and more generally two Euclidean subspaces (A line can be considered as one Euclidean subspace.) are orthogonal if their directions (the associated vector spaces of the Euclidean subspaces) are orthogonal. Two orthogonal lines that intersect are said
6608: 2059: 7517: 1801: 4594:{\displaystyle \operatorname {angle} (\lambda x,\mu y)={\begin{cases}\operatorname {angle} (x,y)\qquad \qquad {\text{if }}\lambda {\text{ and }}\mu {\text{ have the same sign}}\\\pi -\operatorname {angle} (x,y)\qquad {\text{otherwise}}.\end{cases}}} 2271: 2617: 6995: 4156: 3045: 6478: 6394: 1646: 6300: 3626: 8319:, that is, there is no property of the space that allows distinguishing between two points or two lines. Therefore, a more isotropic definition is commonly used, which consists as defining a projective space as the set of the 2321: 1939: 1359: 6720: 4303: 5662: 1916:) has two sorts of subspaces: its Euclidean subspaces and its linear subspaces. Linear subspaces are Euclidean subspaces and a Euclidean subspace is a linear subspace if and only if it contains the zero vector. 309:
all geometry by starting from a few very basic properties, which are abstracted from the physical world, and cannot be mathematically proved because of the lack of more basic tools. These properties are called
7404: 5788: 4720: 1073: 6981:{\displaystyle {\begin{aligned}E&\to \mathbb {R} ^{n}\\P&\mapsto {\Bigl (}e_{1}\cdot {\overrightarrow {OP}},\dots ,e_{n}\cdot {\overrightarrow {OP}}{\Bigr )},{\vphantom {\frac {(}{}}}\end{aligned}}} 4671: 3496: 3450: 3365:
are orthogonal if every nonzero vector of the first one is perpendicular to every nonzero vector of the second one. This implies that the intersection of the linear subspaces is reduced to the zero vector.
1093:
For any vector space, the addition acts freely and transitively on the vector space itself. Thus a Euclidean vector space can be viewed as a Euclidean space that has itself as the associated vector space.
8024:
of a segment as its equivalence class. One must thus prove that this length satisfies properties that characterize nonnegative real numbers. Artin proved this with axioms equivalent to those of Hilbert.
8821: 2789:. For this reason, and for historical reasons, the dot notation is more commonly used than the bracket notation for the inner product of Euclidean spaces. This article will follow this usage; that is 419:
In order to make all of this mathematically precise, the theory must clearly define what is a Euclidean space, and the related notions of distance, angle, translation, and rotation. Even when used in
8823:. For that, it suffices to prove that the square of the norm of the left-hand side is zero. Using the bilinearity of the inner product, this squared norm can be expanded into a linear combination of 7419: 6517: 5573: 9298:
Schläfli ... discovered them before 1853 -- a time when Cayley, Grassman and Möbius were the only other people who had ever conceived of the possibility of geometry in more than three dimensions.
7000: 6839: 2622: 7787:, which are rigid transformations that fix a hyperplane and are not the identity. They are also the transformations consisting in changing the sign of one coordinate over some Euclidean frame. 2564:
The concept of parallel subspaces has been extended to subspaces of different dimensions: two subspaces are parallel if the direction of one of them is contained in the direction to the other.
1724: 2197: 3608: 7747: 7558: 3208: 2887: 8611: 6182: 2548: 6825: 5279: 5209: 1717: 1495: 795: 7337: 6653: 5344: 5310: 5050: 4220: 3363: 3288: 2936: 2599: 1914: 1887: 1857: 1830: 1683: 1553: 1526: 1325: 1179: 841: 9016: 6065: 5166: 5114: 4893: 396:
around a fixed point in the plane, in which all points in the plane turn around that fixed point through the same angle. One of the basic tenets of Euclidean geometry is that two
5476: 5397: 2819: 2751: 4982: 2966: 7869: 5913: 1215: 591: 7184: 1250: 1124: 957: 707: 678: 620: 556: 499: 273: 233: 204: 8957: 7653: 7583:. The restriction to this stabilizer of above group homomorphism is an isomorphism. So the isometries that fix a given point form a group isomorphic to the orthogonal group. 6119: 717:
manner (that is, without choosing a preferred basis and a preferred origin). Another reason is that there is no standard origin nor any standard basis in the physical world.
6510: 6341: 8910: 8866: 6763: 5729: 1579: 6191: 2172:{\displaystyle {\Bigl \{}O+(1-\lambda ){\overrightarrow {OP}}+\lambda {\overrightarrow {OQ}}\mathrel {\Big |} \lambda \in \mathbb {R} {\Bigr \}},{\vphantom {\frac {(}{}}}} 7692: 5693: 4936: 4750:
are arbitrary points, one on each half-line. Although this is less used, one can define similarly the angle of segments or half-lines that do not share an initial point.
3334: 9045: 7289: 5514: 2494: 4091: 3116: 6430: 6346: 5417: 8731:
If the condition of being a bijection is removed, a function preserving the distance is necessarily injective, and is an isometry from its domain to its image.
6670: 4227: 2708:{\displaystyle {\begin{aligned}{\overrightarrow {E}}\times {\overrightarrow {E}}&\to \mathbb {R} \\(x,y)&\mapsto \langle x,y\rangle \end{aligned}}} 7143:{\displaystyle {\begin{aligned}\mathbb {R} ^{n}&\to E\\(x_{1}\dots ,x_{n})&\mapsto \left(O+x_{1}e_{1}+\dots +x_{n}e_{n}\right).\end{aligned}}} 3616:. Its proof is easy in this context, as, expressing this in terms of the inner product, one has, using bilinearity and symmetry of the inner product: 384:
satisfying certain relationships, expressible in terms of distance and angles. For example, there are two fundamental operations (referred to as
446:
The standard way to mathematically define a Euclidean space, as carried out in the remainder of this article, is as a set of points on which a
1934:
is a Euclidean subspace of dimension one. Since a vector space of dimension one is spanned by any nonzero vector, a line is a set of the form
2455:
if they have the same direction (i.e., the same associated vector space). Equivalently, they are parallel, if there is a translation vector
1077:
As previously explained, some of the basic properties of Euclidean spaces result from the structure of affine space. They are described in
5578: 2423:{\displaystyle PQ=QP={\Bigl \{}P+\lambda {\overrightarrow {PQ}}\mathrel {\Big |} 0\leq \lambda \leq 1{\Bigr \}}.{\vphantom {\frac {(}{}}}} 2019:{\displaystyle {\Bigl \{}P+\lambda {\overrightarrow {PQ}}\mathrel {\Big |} \lambda \in \mathbb {R} {\Bigr \}},{\vphantom {\frac {(}{}}}} 1450:{\displaystyle {\overrightarrow {F}}={\Bigl \{}{\overrightarrow {PQ}}\mathrel {\Big |} P\in F,Q\in F{\Bigr \}}{\vphantom {\frac {(}{}}}} 9343: 7360: 5744: 4676: 1029: 4630: 3455: 3409: 6396:
of the associated Euclidean vector spaces. This implies that two isometric Euclidean spaces have the same dimension. Conversely, if
392:, which means a shifting of the plane so that every point is shifted in the same direction and by the same distance. The other is 3518: 8743: 333:, and showed that these allow reducing geometric problems to algebraic computations with numbers. This reduction of geometry to 3133: 2847: 8547: 8367:, where this sum is less than 180°. Their introduction in the second half of 19th century, and the proof that their theory is 6128: 8171: 5519: 5993: 2961:) between two points of a Euclidean space is the norm of the translation vector that maps one point to the other; that is 7568:. The kernel of this homomorphism is the translation group, showing that it is a normal subgroup of the Euclidean group. 972:
denotes an action of a vector on a point. This notation is not ambiguous, as, to distinguish between the two meanings of
173:
There is essentially only one Euclidean space of each dimension; that is, all Euclidean spaces of a given dimension are
8372: 8057:. It is also widely used in all technical areas that are concerned with shapes, figure, location and position, such as 897: 9446: 9396: 9278: 9256: 9223: 9195: 8651: 6074: 5819:
on it, which is the same as a Euclidean frame, except that the basis is not required to be orthonormal. This define
431:, measurement instruments, and so on. A purely mathematical definition of Euclidean space also ignores questions of 8407:
is a space that in the neighborhood of each point resembles a Euclidean space. In technical terms, a manifold is a
6733: 367:, the definition of Euclidean space remained unchanged until the end of 19th century. The introduction of abstract 17: 8498: 7512:{\displaystyle {\overrightarrow {f}}{\Bigl (}{\overrightarrow {OP}}{\Bigr )}=f(P)-f(O).{\vphantom {\frac {(}{}}}} 4757:
is the angle of two segments, one on each line, the angle of any two other segments, one on each line, is either
8315:
lines meet in exactly one point". Projective space share with Euclidean and affine spaces the property of being
7719: 7530: 3307: 9336: 9287: 7259: 7897:
of a Euclidean space equals its dimension. This implies that Euclidean spaces of different dimensions are not
6603:{\displaystyle f(P)=O'+{\overrightarrow {f}}{\Bigl (}{\overrightarrow {OP}}{\Bigr )}{\vphantom {\frac {(}{}}}} 2517: 2276: 1134:. The importance of this particular example of Euclidean space lies in the fact that every Euclidean space is 9315: 8089: 5947: 4320: 8243:
have always two intersection points (possibly not distinct) in the complex affine space. Therefore, most of
6772: 5226: 5184: 2464: 1692: 1470: 770: 9650: 8465:
Euclidean spaces are trivially Riemannian manifolds. An example illustrating this well is the surface of a
8136: 7315: 6631: 6069:
In the case of a Euclidean vector space, an isometry that maps the origin to the origin preserves the norm
5322: 5288: 5000: 4198: 3341: 3266: 2914: 2577: 1892: 1865: 1835: 1808: 1796:{\displaystyle P+{\overrightarrow {V}}={\Bigl \{}P+v\mathrel {\Big |} v\in {\overrightarrow {V}}{\Bigr \}}} 1661: 1531: 1504: 1303: 1157: 819: 8966: 8231:
As soon as non-linear questions are considered, it is generally useful to consider affine spaces over the
5119: 5067: 4846: 9645: 9635: 9431: 9310: 8450:
at the points of the manifold (these tangent spaces are thus Euclidean vector spaces). This results in a
5943: 5422: 5353: 4831: 2792: 2778: 2724: 756:
such that the associated vector space is a Euclidean vector space. Euclidean spaces are sometimes called
236: 4941: 111: 8643: 8248: 7842: 7709: 5964:
This way of defining coordinates extends easily to other mathematical structures, and in particular to
5886: 4361: 1282:
and include the concepts of lines, subspaces, and parallelism, which are detailed in next subsections.
1188: 564: 450: 8311:" to Euclidean spaces, and, more generally to affine spaces, in order to make true the assertion "two 7160: 2266:{\displaystyle {\bigl \{}(1-\lambda )P+\lambda Q\mathrel {\big |} \lambda \in \mathbb {R} {\bigr \}}.} 1226: 1100: 683: 654: 596: 532: 475: 249: 209: 180: 9329: 9305: 8915: 8517: 7790:
As the special Euclidean group is a subgroup of index two of the Euclidean group, given a reflection
7616: 6123:
since the norm of a vector is its distance from the zero vector. It preserves also the inner product
8502: 7932:
The definition of Euclidean spaces that has been described in this article differs fundamentally of
6483: 6314: 4497: 9366: 9291: 9206: 8870: 8826: 8690: 8482: 8371:(if Euclidean geometry is not contradictory) is one of the paradoxes that are at the origin of the 8271: 8252: 8187: 8116: 8003: 7937: 7784: 7705: 5698: 5053: 864: 802: 409: 154: 8439:. However, none of these types of "resemblance" respect distances and angles, even approximately. 8423:
of a Euclidean space. Manifolds can be classified by increasing degree of this "resemblance" into
7909:) if and only if it is homeomorphic to an open subset of a Euclidean space of the same dimension. 7822: 6728:
to the zero vector and has the identity as associated linear map. The inverse isometry is the map
344:
Euclidean geometry was not applied in spaces of dimension more than three until the 19th century.
9640: 9574: 9569: 9549: 8428: 8224:. Affine spaces have many other uses in mathematics. In particular, as they are defined over any 8108: 7662: 7521:
It is straightforward to prove that this is a linear map that does not depend from the choice of
7153:
This means that, up to an isomorphism, there is exactly one Euclidean space of a given dimension.
5939: 5846: 5671: 4902: 2610: 992: 73: 57: 8251:. The shapes that are studied in algebraic geometry in these affine spaces are therefore called 9559: 9554: 9534: 9021: 8506: 8347: 8263: 7967: 7252: 4772: 4722:
As the multiplication of vectors by positive numbers do not change the angle, the angle of two
1274:
Some basic properties of Euclidean spaces depend only on the fact that a Euclidean space is an
860: 651:
A reason for introducing such an abstract definition of Euclidean spaces, and for working with
466: 393: 389: 9564: 9544: 9539: 8013: 7951:. The presentation of Euclidean spaces given in this article, is essentially issued from his 7894: 5481: 4840:(in fact, infinitely many in dimension higher than one, and two in dimension one), that is a 4434: 4151:{\displaystyle {\overrightarrow {AB}}\cdot {\overrightarrow {AC}}=0{\vphantom {\frac {(}{}}}} 3234: 405: 330: 767:
is a Euclidean space, its associated vector space (Euclidean vector space) is often denoted
114:
introduced Euclidean space for modeling the physical space. Their work was collected by the
9233: 9187: 8424: 8221: 8017: 7991: 7902: 7713: 7225: 7207: 4995: 4841: 3122: 3040:{\displaystyle d(P,Q)={\Bigl \|}{\overrightarrow {PQ}}{\Bigr \|}.{\vphantom {\frac {(}{}}}} 561:
It follows that everything that can be said about a Euclidean space can also be said about
436: 408:) if one can be transformed into the other by some sequence of translations, rotations and 318:
in modern language. This way of defining Euclidean space is still in use under the name of
297: 50: 6473:{\displaystyle {\overrightarrow {f}}\colon {\overrightarrow {E}}\to {\overrightarrow {F}}} 6389:{\displaystyle {\overrightarrow {f}}\colon {\overrightarrow {E}}\to {\overrightarrow {F}}} 3226:
is smaller than the sum of the lengths of the other edges. This is the origin of the term
3088: 2561:
It follows that in a Euclidean plane, two lines either meet in one point or are parallel.
8: 9441: 9436: 8694: 8655: 8451: 8398: 8364: 8331: 8225: 8161: 7963: 7576: 3613: 3126: 2606: 2555: 2438: 734: 458: 305: 100: 8084:
Space of dimensions higher than three occurs in several modern theories of physics; see
9615: 9456: 9411: 9245: 8675: 8639: 8536: 8356: 8335: 8308: 8244: 8203: 8100: 7995: 7971: 7836: 7697: 7561: 6305: 5820: 5402: 4387: 4172: 2948: 2900: 428: 319: 147: 128: 61: 1641:{\displaystyle F={\Bigl \{}P+v\mathrel {\Big |} v\in {\overrightarrow {F}}{\Bigr \}}.} 1081:
and its subsections. The properties resulting from the inner product are explained in
345: 9451: 9274: 9252: 9219: 9191: 8669: 8436: 8408: 8360: 8078: 8074: 8034: 7906: 7832: 7769: 6295:{\displaystyle x\cdot y={\tfrac {1}{2}}\left(\|x+y\|^{2}-\|x\|^{2}-\|y\|^{2}\right).} 5806: 4837: 2786: 2718: 1151: 979:
The fact that the action is free and transitive means that, for every pair of points
518: 447: 397: 385: 364: 293: 115: 8202:
of its definition, or, more precisely for proving that its theory is consistent, if
7802:
is an example of a rigid transformation that is not a rigid motion or a reflection.
326: 177:. Therefore it is usually possible to work with a specific Euclidean space, denoted 9381: 9240: 9211: 8722:
It may depend on the context or the author whether a subspace is parallel to itself
8376: 8302: 8085: 7952: 7872: 7799: 7565: 845: 158: 8135:
not of a geometrical nature. An example among many is the usual representation of
9426: 9229: 8532: 8524: 8443: 8432: 8259: 8240: 8166: 8093: 7917: 7913: 7887: 7810: 7298: 7203: 5177: 4312: 1925: 1686: 1464: 1291: 1279: 96: 34:
A point in three-dimensional Euclidean space can be located by three coordinates.
9210:, Wiley Classics Library, New York: John Wiley & Sons Inc., pp. x+214, 8278:
of degree higher than two has no point in the affine plane over the rationals."
7293:
They are in bijective correspondence with vectors. This is a reason for calling
352:, using both synthetic and algebraic methods, and discovered all of the regular 9508: 9493: 8699: 8540: 8513: 8510: 8286: 8232: 8131:. It is common to represent in a Euclidean space mathematical objects that are 8124: 7979: 5869: 4723: 4366: 432: 357: 166: 99:. The qualifier "Euclidean" is used to distinguish Euclidean spaces from other 92: 46: 7749:
is a normal subgroup of index two of the Euclidean group, which is called the
2275:
A standard convention allows using this formula in every Euclidean space, see
296:
as an abstraction of our physical space. Their great innovation, appearing in
9629: 9498: 9266: 8683: 8647: 8494: 8455: 8447: 8282: 8267: 8104: 7983: 7959: 5865: 3250: 3246: 2041:
there is exactly one line that passes through (contains) two distinct points.
1131: 143: 142:, which either were considered as evident (for example, there is exactly one 9518: 9483: 9376: 8470: 8416: 8412: 8388: 8324: 8290: 8275: 8215: 8058: 7898: 7828: 5981: 5958: 5873: 5831: 5816: 5812: 4398: 2892: 2781:
has been chosen, as, in this case, the inner product of two vectors is the
2284: 1275: 1269: 868: 749: 462: 368: 240: 162: 157:, the old postulates were re-formalized to define Euclidean spaces through 9215: 7794:, every rigid transformation that is not a rigid motion is the product of 7297:
the vector space associated to a Euclidean space. The translations form a
9603: 9386: 8420: 8368: 8320: 8199: 7987: 7975: 7944: 7924:(that is, contained in a ball). In particular, closed balls are compact. 7921: 7783:
Typical examples of rigid transformations that are not rigid motions are
7716:
two of the orthogonal group. Its inverse image by the group homomorphism
7564:
from the Euclidean group onto the group of linear isometries, called the
6715:{\displaystyle P\mapsto {\overrightarrow {OP}},{\vphantom {\frac {(}{}}}} 5876: 5061: 4896: 4298:{\displaystyle \theta =\arccos \left({\frac {x\cdot y}{|x|\,|y|}}\right)} 3402: 2782: 1135: 1127: 851: 753: 738: 522: 506: 424: 338: 276: 174: 65: 8509:
is an affine space with an associated real vector space equipped with a
8442:
Distances and angles can be defined on a smooth manifold by providing a
7955:, with the emphasis given on the groups of translations and isometries. 643: 9598: 9478: 8528: 8478: 8474: 8375:
of the beginning of 20th century, and motivated the systematization of
8103:, Euclidean spaces are also widely used in other areas of mathematics. 8070: 8066: 8008: 7948: 7777: 7344: 5845:
points that are not contained in a hyperplane. An affine basis define
2036:
are two distinct points of the Euclidean space as a part of the line.
9579: 9488: 9401: 9352: 8539:. It is a four-dimensional space, where the metric is defined by the 8316: 8195: 8128: 8120: 8054: 8050: 7883: 7806: 7224:. The rigid transformations of a Euclidean space form a group (under 5985: 4316: 2043:
This implies that two distinct lines intersect in at most one point.
381: 311: 138: 7920:. That is, a closed subset of a Euclidean space is compact if it is 5827:
for emphasizing that the basis vectors are not pairwise orthogonal.
5657:{\displaystyle v=\alpha _{1}e_{1}+\alpha _{2}e_{2}+\alpha _{3}e_{3}} 4353:
Angles are not useful in a Euclidean line, as they can be only 0 or
465:, and this allows defining lines, planes, subspaces, dimension, and 30: 9503: 9466: 9391: 9153: 8687: 8459: 8458:
do not exist in a Riemannian manifold, but their role is played by
8404: 8394: 8363:, where the sum of the angles of a triangle is more than 180°, and 8312: 8112: 7879: 7773: 5977: 5965: 5852:
Many other coordinates systems can be defined on a Euclidean space
3223: 2896: 2188:
In a Euclidean vector space, the zero vector is usually chosen for
353: 42: 8115:
is a space that is locally approximated by Euclidean spaces. Most
6990:
which is an isometry of Euclidean spaces. The inverse isometry is
3015: 2993: 9513: 8703: 8635: 8062: 8046: 8042: 4615:
are three points in a Euclidean space, the angle of the segments
420: 334: 133: 104: 7399:{\displaystyle {\overrightarrow {PQ}},{\vphantom {\frac {(}{}}}} 5797: 5783:{\displaystyle {\overrightarrow {OP}}.{\vphantom {\frac {(}{}}}} 4715:{\displaystyle {\overrightarrow {AC}}.{\vphantom {\frac {(}{}}}} 1068:{\displaystyle {\overrightarrow {PQ}}{\vphantom {\frac {)}{}}}.} 9116: 9114: 8466: 8236: 7933: 7886:
around each of their points. In other words, open balls form a
4666:{\displaystyle {\overrightarrow {AB}}{\vphantom {\frac {(}{}}}} 3491:{\displaystyle {\overrightarrow {AC}}{\vphantom {\frac {)}{}}}} 3445:{\displaystyle {\overrightarrow {AB}}{\vphantom {\frac {)}{}}}} 816:, and are commonly denoted by capital letters. The elements of 440: 401: 119: 8654:
of this manifold at a point is a function of the value of the
8307:
Originally, projective spaces have been introduced by adding "
7708:
is the normal subgroup of the orthogonal group that preserves
593:
Therefore, many authors, especially at elementary level, call
363:
Despite the wide use of Descartes' approach, which was called
9470: 9131: 9129: 8330:
As for affine spaces, projective spaces are defined over any
8198:
the space in a Euclidean space is a standard way for proving
8191: 8038: 4167: 2891:
The inner product and the norm allows expressing and proving
315: 9321: 9111: 7905:
asserts that a subset of a Euclidean space is open (for the
5961:, the longitude passes discontinuously from –180° to +180°. 4386:. In this case, the angle of two vectors can have any value 2046:
A more symmetric representation of the line passing through
521:
of the space of translations is equivalent with defining an
146:
passing through two points), or seemed impossible to prove (
4587: 3125:, as it is positive definite, symmetric, and satisfies the 91:
equal to one or two, they are commonly called respectively
9126: 8816:{\displaystyle f(\lambda x+\mu y)-\lambda f(x)-\mu f(y)=0} 8123:
in a Euclidean space of higher dimension. For example, an
2903:. The next subsection describe the most fundamental ones. 976:, it suffices to look at the nature of its left argument. 9065: 9063: 8247:
is built in complex affine spaces and affine spaces over
7805:
All groups that have been considered in this section are
7212:
An isometry from a Euclidean space onto itself is called
3222:. This inequality means that the length of any edge of a 469:. The inner product allows defining distance and angles. 337:
was a major change in point of view, as, until then, the
153:
After the introduction at the end of the 19th century of
7776:(the rigid motions that fix at least a point), and also 3233:
With the Euclidean distance, every Euclidean space is a
2554:
is a line (subspace of dimension one), this property is
136:, by starting from a few fundamental properties, called 8186:
Since the introduction, at the end of 19th century, of
5950:
coordinate systems (dimension 3) are defined this way.
5516:
as a convention) in a 3-dimensional Euclidean space is
5181:
is a set of data consisting of an orthonormal basis of
2763:
The inner product of a Euclidean space is often called
968:
in the left-hand side is a vector addition; each other
9060: 6619: 6208: 3212:
Moreover, the equality is true if and only if a point
2277:
Affine space § Affine combinations and barycenter
375: 348:
generalized Euclidean geometry to spaces of dimension
9024: 8969: 8918: 8873: 8829: 8746: 8550: 8220:
A Euclidean space is an affine space equipped with a
7845: 7722: 7665: 7619: 7533: 7422: 7363: 7318: 7262: 7163: 6998: 6837: 6775: 6736: 6673: 6634: 6520: 6486: 6433: 6349: 6317: 6194: 6131: 6077: 5996: 5889: 5747: 5701: 5674: 5581: 5568:{\displaystyle (\alpha _{1},\alpha _{2},\alpha _{3})} 5522: 5484: 5425: 5405: 5356: 5325: 5291: 5229: 5187: 5122: 5070: 5003: 4944: 4905: 4849: 4679: 4633: 4461: 4433:
The angle of two vectors does not change if they are
4230: 4201: 4094: 3624: 3521: 3458: 3412: 3344: 3310: 3269: 3136: 3091: 2969: 2917: 2850: 2795: 2727: 2620: 2580: 2520: 2467: 2324: 2200: 2192:; this allows simplifying the preceding formula into 2062: 1942: 1895: 1868: 1838: 1811: 1727: 1695: 1664: 1582: 1534: 1528:
as the associated vector space. This linear subspace
1507: 1473: 1362: 1306: 1229: 1191: 1160: 1103: 1032: 900: 822: 773: 686: 657: 599: 567: 535: 478: 252: 212: 183: 161:. Another definition of Euclidean spaces by means of 9075: 8665: 8235:
as an extension of Euclidean spaces. For example, a
6655:
can be considered as a Euclidean space. Every point
8963:is an isometry, this gives a linear combination of 5399:For example, the Cartesian coordinates of a vector 5056:computes an orthonormal basis such that, for every 4323:, the argument of the arccosine is in the interval 2185:is an arbitrary point (not necessary on the line). 1832:. (The associated vector space of this subspace is 360:) that exist in Euclidean spaces of any dimension. 9244: 9099: 9039: 9010: 8951: 8904: 8860: 8815: 8605: 7863: 7741: 7700:of the translation group and the orthogonal group. 7686: 7647: 7552: 7511: 7398: 7331: 7283: 7178: 7142: 6980: 6819: 6757: 6714: 6647: 6628:is a Euclidean space, its associated vector space 6602: 6504: 6472: 6388: 6335: 6294: 6176: 6113: 6059: 5907: 5782: 5723: 5687: 5656: 5567: 5508: 5470: 5411: 5391: 5338: 5304: 5273: 5203: 5160: 5108: 5044: 4976: 4930: 4887: 4714: 4665: 4593: 4370:of two vectors. The oriented angle of two vectors 4297: 4214: 4176:Positive and negative angles on the oriented plane 4150: 4078: 3602: 3490: 3444: 3357: 3328: 3290:(the associated vector space of a Euclidean space 3282: 3202: 3110: 3039: 2930: 2881: 2813: 2745: 2707: 2593: 2542: 2506:, there exists exactly one subspace that contains 2488: 2422: 2265: 2171: 2018: 1908: 1881: 1851: 1824: 1795: 1711: 1677: 1640: 1547: 1520: 1489: 1449: 1319: 1244: 1209: 1173: 1118: 1067: 951: 835: 789: 760:to distinguish them from Euclidean vector spaces. 701: 672: 614: 585: 550: 493: 427:detached from actual physical locations, specific 267: 227: 198: 9165: 9087: 8266:provide a link between (algebraic) geometry and 7827:The Euclidean distance makes a Euclidean space a 7457: 7435: 6952: 6880: 6581: 6559: 4753:The angle of two lines is defined as follows. If 3808: 3768: 3758: 3718: 2398: 2376: 2345: 2147: 2129: 2065: 1994: 1976: 1945: 1788: 1765: 1749: 1630: 1607: 1591: 1428: 1400: 1378: 9627: 4730:can be defined: it is the angle of the segments 4158:is used since these two vectors are orthogonal. 1181:defines an isomorphism of Euclidean spaces from 461:. The action of translations makes the space an 404:) of the plane should be considered equivalent ( 380:One way to think of the Euclidean plane is as a 341:were defined in terms of lengths and distances. 8355:refers usually to geometrical spaces where the 8228:, they allow doing geometry in other contexts. 8111:are Euclidean vector spaces. More generally, a 8041:in the physical world. It is thus used in many 5281:allows defining Cartesian coordinates for both 2451:of the same dimension in a Euclidean space are 1138:to it. More precisely, given a Euclidean space 647:Origin-free illustration of the Euclidean plane 513:. Conversely, the choice of a point called the 443:, not something expressed in inches or metres. 87:when one wants to specify their dimension. For 4378:is then the opposite of the oriented angle of 871:of a Euclidean vector on the Euclidean space. 439:: the distance in a "mathematical" space is a 9337: 9247:A Short Account of the History of Mathematics 8523:A fundamental example of such a space is the 8037:, Euclidean space has been used for modeling 7947:suggested to define geometries through their 2255: 2237: 2203: 1889:(that is, a Euclidean space that is equal to 8996: 8989: 8977: 8970: 8890: 8874: 8846: 8830: 6304:An isometry of Euclidean vector spaces is a 6275: 6268: 6256: 6249: 6237: 6224: 6105: 6099: 6093: 6078: 5741:are the Cartesian coordinates of the vector 4919: 4906: 4798:of the two lines is the one in the interval 2857: 2851: 2808: 2796: 2740: 2728: 2698: 2686: 1097:A typical case of Euclidean vector space is 709:is that it is often preferable to work in a 287: 9303: 9069: 8341: 8285:has also been widely studied. For example, 8160:It has been suggested that this section be 7986:proposed simpler sets of axioms, which use 7974:, as they do not involve any definition of 7823:Real n-space § Topological properties 7251:The simplest Euclidean transformations are 3603:{\displaystyle |BC|^{2}=|AB|^{2}+|AC|^{2}.} 1126:viewed as a vector space equipped with the 9344: 9330: 7742:{\displaystyle f\to {\overrightarrow {f}}} 7553:{\displaystyle f\to {\overrightarrow {f}}} 5953:For points that are outside the domain of 2911:denotes an arbitrary Euclidean space, and 505:-tuples of real numbers equipped with the 8488: 8485:can be realized as Riemannian manifolds. 8142: 7943:Two different approaches have been used. 7848: 7343:, it is meant an isometry that is also a 7166: 7157:This justifies that many authors talk of 7005: 6854: 5892: 4274: 3203:{\displaystyle d(P,Q)\leq d(P,R)+d(R,Q).} 2938:denotes its vector space of translations. 2882:{\displaystyle \|x\|={\sqrt {x\cdot x}}.} 2656: 2308:in the preceding formulas. It is denoted 2249: 2141: 1988: 1232: 1223:is isomorphic to it, the Euclidean space 1194: 1106: 689: 660: 602: 570: 538: 481: 255: 215: 8606:{\displaystyle x^{2}+y^{2}+z^{2}-t^{2},} 8206:is consistent (which cannot be proved). 7927: 6665:defines an isometry of Euclidean spaces 6343:of Euclidean spaces defines an isometry 6177:{\displaystyle f(x)\cdot f(y)=x\cdot y,} 5796: 4825: 4437:by positive numbers. More precisely, if 4171: 2543:{\displaystyle P+{\overrightarrow {S}}.} 1088: 642: 29: 9286: 9105: 8289:over finite fields are widely used in 7579:of the Euclidean group with respect to 3054: 720: 525:between a Euclidean space of dimension 14: 9628: 9265: 9159: 9135: 9120: 9093: 7571:The isometries that fix a given point 6820:{\displaystyle (O,e_{1},\dots ,e_{n})} 5315:The Cartesian coordinates of a vector 5274:{\displaystyle (O,e_{1},\dots ,e_{n})} 5204:{\displaystyle {\overrightarrow {E}},} 4806:. In an oriented Euclidean plane, the 2942: 1712:{\displaystyle {\overrightarrow {E}},} 1490:{\displaystyle {\overrightarrow {E}}.} 1219:As every Euclidean space of dimension 790:{\displaystyle {\overrightarrow {E}}.} 9325: 9203: 9181: 9171: 9147: 8164:out into another article titled 8020:on segments. One can thus define the 7332:{\displaystyle {\overrightarrow {f}}} 6648:{\displaystyle {\overrightarrow {E}}} 5733:The Cartesian coordinates of a point 5339:{\displaystyle {\overrightarrow {E}}} 5305:{\displaystyle {\overrightarrow {E}}} 5045:{\displaystyle (b_{1},\dots ,b_{n}),} 4810:of two lines belongs to the interval 4215:{\displaystyle {\overrightarrow {E}}} 3358:{\displaystyle {\overrightarrow {E}}} 3283:{\displaystyle {\overrightarrow {E}}} 2931:{\displaystyle {\overrightarrow {E}}} 2594:{\displaystyle {\overrightarrow {E}}} 1919: 1909:{\displaystyle {\overrightarrow {E}}} 1882:{\displaystyle {\overrightarrow {E}}} 1852:{\displaystyle {\overrightarrow {V}}} 1825:{\displaystyle {\overrightarrow {V}}} 1805:is a Euclidean subspace of direction 1678:{\displaystyle {\overrightarrow {V}}} 1548:{\displaystyle {\overrightarrow {F}}} 1521:{\displaystyle {\overrightarrow {F}}} 1320:{\displaystyle {\overrightarrow {E}}} 1174:{\displaystyle {\overrightarrow {E}}} 1082: 1078: 836:{\displaystyle {\overrightarrow {E}}} 356:(higher-dimensional analogues of the 9251:(4th ed.). Dover Publications. 9239: 9081: 9011:{\displaystyle \|x\|^{2},\|y\|^{2},} 8619:) is temporal, and the other three ( 8146: 8012:the following. In Hilbert's axioms, 7347:) in the following way: denoting by 6612:is an isometry of Euclidean spaces. 6060:{\displaystyle d(f(x),f(y))=d(x,y).} 5792: 5161:{\displaystyle (b_{1},\dots ,b_{i})} 5109:{\displaystyle (e_{1},\dots ,e_{i})} 4888:{\displaystyle (e_{1},\dots ,e_{n})} 4836:Every Euclidean vector space has an 4364:Euclidean plane, one can define the 4350:if angles are measured in degrees). 2777:. This is specially the case when a 413: 8296: 7339:of the associated vector space (by 6620:Isometry with prototypical examples 5664:. As the basis is orthonormal, the 5471:{\displaystyle (e_{1},e_{2},e_{3})} 5392:{\displaystyle e_{1},\dots ,e_{n}.} 2814:{\displaystyle \langle x,y\rangle } 2746:{\displaystyle \langle x,x\rangle } 2569: 1263: 1146:, the choice of a point, called an 376:Motivation of the modern definition 24: 8373:foundational crisis in mathematics 8119:can be modeled by a manifold, and 7197: 5834:of a Euclidean space of dimension 4977:{\displaystyle e_{i}\cdot e_{j}=0} 2831:in the remainder of this article. 2300:is the subset of points such that 1459:as the associated vector space of 509:is a Euclidean space of dimension 292:Euclidean space was introduced by 25: 9662: 9296:(3rd ed.). New York: Dover. 8281:Geometry in affine spaces over a 7882:are the subsets that contains an 7864:{\displaystyle \mathbb {R} ^{n},} 5988:preserving the distance, that is 5908:{\displaystyle \mathbb {R} ^{n}.} 1210:{\displaystyle \mathbb {R} ^{n}.} 882:provides a point that is denoted 859:, although, properly speaking, a 586:{\displaystyle \mathbb {R} ^{n}.} 235:, which can be represented using 9410: 8668: 8503:positive definite quadratic form 8481:. More generally, the spaces of 8382: 8334:, and are fundamental spaces of 8151: 7179:{\displaystyle \mathbb {R} ^{n}} 4938:) that are pairwise orthogonal ( 4771:. One of these angles is in the 3302:if their inner product is zero: 3240: 2601:associated to a Euclidean space 1245:{\displaystyle \mathbb {R} ^{n}} 1119:{\displaystyle \mathbb {R} ^{n}} 952:{\displaystyle P+(v+w)=(P+v)+w.} 805:of its associated vector space. 702:{\displaystyle \mathbb {R} ^{n}} 673:{\displaystyle \mathbb {E} ^{n}} 615:{\displaystyle \mathbb {R} ^{n}} 551:{\displaystyle \mathbb {R} ^{n}} 494:{\displaystyle \mathbb {R} ^{n}} 423:theories, Euclidean space is an 268:{\displaystyle \mathbb {R} ^{n}} 228:{\displaystyle \mathbb {E} ^{n}} 199:{\displaystyle \mathbf {E} ^{n}} 186: 8952:{\displaystyle f(x)\cdot f(y).} 8734: 8499:positive definite bilinear form 8209: 7648:{\displaystyle g=t^{-1}\circ f} 6114:{\displaystyle \|f(x)\|=\|x\|,} 4575: 4522: 4521: 132:all properties of the space as 126:, with the great innovation of 9141: 8943: 8937: 8928: 8922: 8886: 8880: 8842: 8836: 8804: 8798: 8786: 8780: 8768: 8750: 8725: 8716: 8469:. In this case, geodesics are 7835:. This topology is called the 7726: 7537: 7500: 7489: 7483: 7474: 7468: 7387: 7266: 7065: 7058: 7029: 7019: 6965: 6875: 6849: 6814: 6776: 6740: 6703: 6677: 6591: 6530: 6524: 6505:{\displaystyle f\colon E\to F} 6496: 6457: 6373: 6336:{\displaystyle f\colon E\to F} 6327: 6156: 6150: 6141: 6135: 6090: 6084: 6051: 6039: 6030: 6027: 6021: 6012: 6006: 6000: 5801:3-dimensional skew coordinates 5771: 5562: 5523: 5503: 5485: 5465: 5426: 5268: 5230: 5155: 5123: 5103: 5071: 5036: 5004: 4882: 4850: 4703: 4654: 4572: 4560: 4518: 4506: 4486: 4468: 4284: 4276: 4270: 4262: 4139: 4059: 4047: 4033: 4021: 3697: 3642: 3630: 3587: 3575: 3561: 3549: 3535: 3523: 3479: 3433: 3194: 3182: 3173: 3161: 3152: 3140: 3104: 3093: 3028: 2985: 2973: 2683: 2676: 2664: 2652: 2432: 2411: 2220: 2208: 2160: 2088: 2076: 2007: 1438: 1053: 937: 925: 919: 907: 103:that were later considered in 13: 1: 9351: 9054: 8905:{\displaystyle \|f(y)\|^{2},} 8861:{\displaystyle \|f(x)\|^{2},} 8646:that has Minkowski spaces as 8411:, such that each point has a 7190:Euclidean space of dimension 6758:{\displaystyle v\mapsto O+v.} 6480:is an isometry, then the map 5971: 5724:{\displaystyle v\cdot e_{i}.} 4994:). More precisely, given any 3389:that share a common endpoint 1327:its associated vector space. 636:Euclidean space of dimension 558:viewed as a Euclidean space. 282: 27:Fundamental space of geometry 8709: 8501:, and so characterized by a 8497:of a real vector space is a 7497: 7384: 6962: 6700: 6588: 5860:, in the following way. Let 5768: 5695:is equal to the dot product 4700: 4651: 4627:is the angle of the vectors 4187:between two nonzero vectors 4136: 3694: 3513:form a right angle, one has 3476: 3430: 3025: 2459:that maps one to the other: 2408: 2157: 2004: 1435: 1285: 1050: 874:The action of a translation 801:of a Euclidean space is the 41:is the fundamental space of 7: 9311:Encyclopedia of Mathematics 9304:Solomentsev, E.D. (2001) , 8740:Proof: one must prove that 8661: 8615:where the last coordinate ( 8249:algebraically closed fields 7901:. Moreover, the theorem of 7816: 7696:the Euclidean group is the 7687:{\displaystyle f=t\circ g,} 5811:As a Euclidean space is an 5688:{\displaystyle \alpha _{i}} 4931:{\displaystyle \|e_{i}\|=1} 4832:Cartesian coordinate system 2779:Cartesian coordinate system 275:equipped with the standard 10: 9667: 9186:(5th ed.), New York: 8644:pseudo-Riemannian manifold 8392: 8386: 8345: 8300: 8253:affine algebraic varieties 8213: 7871:this topology is also the 7820: 7768:Rigid motions include the 7757:. Its elements are called 7598:the translation that maps 7312:defines a linear isometry 7201: 5804: 4829: 4414:equals the negative angle 4165: 3329:{\displaystyle u\cdot v=0} 3244: 2946: 2436: 1923: 1501:is a Euclidean space with 1289: 1267: 457:which is equipped with an 9612: 9591: 9527: 9465: 9419: 9408: 9359: 9184:Elementary Linear Algebra 9047:which simplifies to zero. 9040:{\displaystyle x\cdot y,} 7410:is an arbitrary point of 7284:{\displaystyle P\to P+v.} 5350:on the orthonormal basis 4782:, and the other being in 4321:Cauchy–Schwarz inequality 1862:A Euclidean vector space 1300:be a Euclidean space and 288:History of the definition 8483:non-Euclidean geometries 8446:Euclidean metric on the 8429:differentiable manifolds 8342:Non-Euclidean geometries 8262:and more generally over 8188:non-Euclidean geometries 8117:non-Euclidean geometries 8109:differentiable manifolds 8028: 7938:non-Euclidean geometries 7706:special orthogonal group 7301:of the Euclidean group. 7218:Euclidean transformation 6829:allows defining the map 5419:on an orthonormal basis 5346:are the coefficients of 5171:Given a Euclidean space 4541: have the same sign 4161: 3338:Two linear subspaces of 1930:In a Euclidean space, a 1254:standard Euclidean space 1252:is sometimes called the 892:. This action satisfies 865:geometric transformation 733:is a finite-dimensional 625:standard Euclidean space 155:non-Euclidean geometries 107:and modern mathematics. 72:of any positive integer 45:, intended to represent 8359:is false. They include 8327:of dimension one more. 8264:algebraic number fields 8258:Affine spaces over the 7751:special Euclidean group 5940:polar coordinate system 5847:barycentric coordinates 5509:{\displaystyle (x,y,z)} 4453:are real numbers, then 4390:an integer multiple of 3216:belongs to the segment 2753:is always positive for 2611:symmetric bilinear form 1083:§ Metric structure 1079:§ Affine structure 991:, there is exactly one 855:. They are also called 758:Euclidean affine spaces 400:(usually considered as 388:) on the plane. One is 58:three-dimensional space 9182:Anton, Howard (1987), 9041: 9012: 8953: 8906: 8862: 8817: 8686:, a generalization to 8607: 8507:pseudo-Euclidean space 8489:Pseudo-Euclidean space 8353:Non-Euclidean geometry 8348:Non-Euclidean geometry 8143:Other geometric spaces 7865: 7798:and a rigid motion. A 7743: 7712:. It is a subgroup of 7688: 7649: 7554: 7513: 7400: 7333: 7285: 7180: 7144: 6982: 6821: 6759: 6716: 6649: 6604: 6506: 6474: 6404:are Euclidean spaces, 6390: 6337: 6296: 6178: 6115: 6061: 5942:(dimension 2) and the 5927:are the components of 5909: 5815:, one can consider an 5802: 5784: 5725: 5689: 5658: 5569: 5510: 5478:(that may be named as 5472: 5413: 5393: 5340: 5312:in the following way. 5306: 5275: 5205: 5162: 5110: 5046: 4978: 4932: 4889: 4716: 4667: 4595: 4299: 4216: 4177: 4152: 4080: 3604: 3492: 3446: 3359: 3330: 3284: 3204: 3112: 3085:. It is often denoted 3077:between its endpoints 3041: 2932: 2883: 2815: 2747: 2709: 2595: 2544: 2490: 2489:{\displaystyle T=S+v.} 2424: 2267: 2173: 2020: 1910: 1883: 1853: 1826: 1797: 1713: 1679: 1642: 1549: 1522: 1491: 1451: 1321: 1246: 1211: 1175: 1120: 1069: 953: 837: 791: 729:Euclidean vector space 703: 674: 648: 616: 587: 552: 495: 269: 229: 200: 35: 9216:10.1002/9781118164518 9204:Artin, Emil (1988) , 9042: 9013: 8954: 8907: 8863: 8818: 8608: 8425:topological manifolds 8393:Further information: 8272:Fermat's Last Theorem 8127:can be modeled by an 8088:. They occur also in 7928:Axiomatic definitions 7912:Euclidean spaces are 7895:topological dimension 7866: 7744: 7689: 7650: 7555: 7514: 7401: 7334: 7308:of a Euclidean space 7304:A Euclidean isometry 7295:space of translations 7286: 7181: 7145: 6983: 6822: 6760: 6717: 6650: 6605: 6507: 6475: 6391: 6338: 6297: 6179: 6116: 6062: 5910: 5883:to an open subset of 5800: 5785: 5726: 5690: 5659: 5570: 5511: 5473: 5414: 5394: 5341: 5307: 5276: 5206: 5163: 5111: 5047: 4979: 4933: 4890: 4826:Cartesian coordinates 4717: 4668: 4596: 4445:are two vectors, and 4300: 4217: 4175: 4153: 4081: 3605: 3493: 3447: 3360: 3331: 3285: 3235:complete metric space 3205: 3113: 3042: 2933: 2905:In these subsections, 2884: 2816: 2748: 2710: 2596: 2545: 2491: 2425: 2292:, joining the points 2268: 2174: 2021: 1911: 1884: 1854: 1827: 1798: 1714: 1680: 1643: 1550: 1523: 1497:A Euclidean subspace 1492: 1467:(vector subspace) of 1452: 1322: 1247: 1212: 1176: 1121: 1089:Prototypical examples 1085:and its subsections. 1070: 954: 838: 792: 704: 675: 646: 617: 588: 553: 496: 455:space of translations 331:Cartesian coordinates 270: 237:Cartesian coordinates 230: 201: 33: 9528:Dimensions by number 9273:, Berlin: Springer, 9162:, Proposition 9.1.3. 9022: 8967: 8916: 8871: 8827: 8744: 8702:, an application in 8548: 8471:arcs of great circle 8090:configuration spaces 8018:equivalence relation 7903:invariance of domain 7888:base of the topology 7843: 7720: 7663: 7617: 7531: 7505: 7420: 7392: 7361: 7316: 7260: 7222:rigid transformation 7208:Rigid transformation 7161: 6996: 6970: 6835: 6773: 6734: 6708: 6671: 6632: 6596: 6518: 6484: 6431: 6347: 6315: 6192: 6129: 6075: 5994: 5887: 5776: 5745: 5699: 5672: 5579: 5520: 5482: 5423: 5403: 5354: 5323: 5289: 5227: 5223:. A Cartesian frame 5185: 5120: 5068: 5054:Gram–Schmidt process 5001: 4942: 4903: 4847: 4708: 4677: 4659: 4631: 4459: 4228: 4199: 4144: 4092: 3702: 3622: 3519: 3484: 3456: 3438: 3410: 3342: 3308: 3267: 3255:Two nonzero vectors 3134: 3111:{\displaystyle |PQ|} 3089: 3033: 2967: 2957:(more precisely the 2915: 2848: 2793: 2725: 2618: 2578: 2518: 2465: 2416: 2322: 2198: 2165: 2060: 2012: 1940: 1893: 1866: 1836: 1809: 1725: 1693: 1662: 1580: 1532: 1505: 1471: 1443: 1360: 1304: 1227: 1189: 1158: 1101: 1058: 1030: 898: 820: 771: 721:Technical definition 684: 655: 597: 565: 533: 476: 250: 210: 181: 9651:Norms (mathematics) 9150:, pp. 209–215) 8695:functional analysis 8656:gravitational field 8473:, which are called 8452:Riemannian manifold 8399:Riemannian manifold 8365:hyperbolic geometry 8270:. For example, the 7968:Euclid's postulates 7958:On the other hand, 7577:stabilizer subgroup 7506: 7498: 7393: 7385: 6971: 6963: 6709: 6701: 6597: 6589: 5868:(or, more often, a 5823:, sometimes called 5777: 5769: 4726:with initial point 4709: 4701: 4660: 4652: 4397:. In particular, a 4180:The (non-oriented) 4145: 4137: 3703: 3695: 3614:Pythagorean theorem 3485: 3477: 3439: 3431: 3228:triangle inequality 3127:triangle inequality 3034: 3026: 2943:Distance and length 2607:inner product space 2510:and is parallel to 2439:Parallel (geometry) 2417: 2409: 2166: 2158: 2013: 2005: 1555:is also called the 1444: 1436: 1059: 1051: 993:displacement vector 867:resulting from the 735:inner product space 437:physical dimensions 79:, which are called 9646:Homogeneous spaces 9636:Euclidean geometry 9457:Degrees of freedom 9360:Dimensional spaces 9037: 9008: 8949: 8902: 8858: 8813: 8676:Mathematics portal 8640:general relativity 8603: 8537:special relativity 8477:in the context of 8437:analytic manifolds 8377:axiomatic theories 8357:parallel postulate 8336:algebraic geometry 8309:points at infinity 8245:algebraic geometry 8204:Euclidean geometry 8101:Euclidean geometry 7972:synthetic geometry 7962:proposed a set of 7861: 7837:Euclidean topology 7755:displacement group 7739: 7698:semidirect product 7684: 7645: 7562:group homomorphism 7550: 7509: 7396: 7329: 7281: 7232:and often denoted 7214:Euclidean isometry 7176: 7140: 7138: 6978: 6976: 6817: 6767:A Euclidean frame 6755: 6712: 6645: 6600: 6502: 6470: 6386: 6333: 6306:linear isomorphism 6292: 6217: 6174: 6111: 6057: 5905: 5821:affine coordinates 5803: 5780: 5721: 5685: 5654: 5565: 5506: 5468: 5409: 5389: 5336: 5302: 5271: 5219:and often denoted 5201: 5158: 5106: 5042: 4974: 4928: 4885: 4796:non-oriented angle 4712: 4663: 4591: 4586: 4295: 4212: 4178: 4148: 4076: 4074: 3600: 3488: 3442: 3355: 3326: 3280: 3200: 3121:The distance is a 3108: 3037: 2959:Euclidean distance 2949:Euclidean distance 2928: 2901:Euclidean geometry 2879: 2811: 2787:coordinate vectors 2743: 2705: 2703: 2591: 2550:In the case where 2540: 2486: 2420: 2263: 2169: 2016: 1920:Lines and segments 1906: 1879: 1849: 1822: 1793: 1709: 1675: 1638: 1545: 1518: 1487: 1447: 1336:Euclidean subspace 1317: 1278:. They are called 1242: 1207: 1171: 1116: 1065: 949: 833: 787: 699: 670: 649: 612: 583: 548: 491: 320:synthetic geometry 265: 225: 196: 148:parallel postulate 62:Euclidean geometry 36: 9623: 9622: 9432:Lebesgue covering 9397:Algebraic variety 9306:"Euclidean space" 9293:Regular Polytopes 9207:Geometric Algebra 9084:, pp. 50–62. 8409:topological space 8361:elliptic geometry 8274:can be stated "a 8184: 8183: 8179: 8079:technical drawing 8075:industrial design 8004:Geometric Algebra 7992:Birkhoff's axioms 7970:. They belong to 7907:subspace topology 7839:. In the case of 7833:topological space 7737: 7594:an isometry, and 7548: 7504: 7503: 7453: 7431: 7391: 7390: 7377: 7327: 6969: 6968: 6948: 6911: 6707: 6706: 6693: 6643: 6595: 6594: 6577: 6555: 6468: 6455: 6442: 6384: 6371: 6358: 6216: 5849:for every point. 5807:Coordinate system 5793:Other coordinates 5775: 5774: 5761: 5412:{\displaystyle v} 5334: 5300: 5196: 4838:orthonormal basis 4707: 4706: 4693: 4658: 4657: 4647: 4579: 4542: 4534: 4526: 4289: 4210: 4143: 4142: 4126: 4108: 4008: 3990: 3972: 3954: 3929: 3911: 3890: 3872: 3854: 3836: 3804: 3786: 3754: 3736: 3701: 3700: 3690: 3672: 3483: 3482: 3472: 3437: 3436: 3426: 3353: 3278: 3032: 3031: 3011: 2926: 2874: 2719:positive definite 2646: 2633: 2609:. This implies a 2589: 2574:The vector space 2535: 2415: 2414: 2372: 2164: 2163: 2125: 2104: 2011: 2010: 1972: 1904: 1877: 1847: 1820: 1784: 1742: 1704: 1673: 1626: 1543: 1516: 1482: 1442: 1441: 1396: 1371: 1315: 1280:affine properties 1169: 1152:orthonormal basis 1057: 1056: 1046: 846:Euclidean vectors 831: 782: 519:orthonormal basis 448:real vector space 365:analytic geometry 303:was to build and 170:Euclidean space. 49:. Originally, in 16:(Redirected from 9658: 9420:Other dimensions 9414: 9382:Projective space 9346: 9339: 9332: 9323: 9322: 9318: 9300: 9283: 9262: 9250: 9241:Ball, W.W. Rouse 9236: 9200: 9175: 9169: 9163: 9157: 9151: 9145: 9139: 9133: 9124: 9118: 9109: 9103: 9097: 9091: 9085: 9079: 9073: 9070:Solomentsev 2001 9067: 9048: 9046: 9044: 9043: 9038: 9017: 9015: 9014: 9009: 9004: 9003: 8985: 8984: 8962: 8958: 8956: 8955: 8950: 8911: 8909: 8908: 8903: 8898: 8897: 8867: 8865: 8864: 8859: 8854: 8853: 8822: 8820: 8819: 8814: 8738: 8732: 8729: 8723: 8720: 8678: 8673: 8672: 8612: 8610: 8609: 8604: 8599: 8598: 8586: 8585: 8573: 8572: 8560: 8559: 8444:smoothly varying 8433:smooth manifolds 8379:in mathematics. 8303:Projective space 8297:Projective space 8260:rational numbers 8175: 8155: 8154: 8147: 8094:physical systems 8086:Higher dimension 7953:Erlangen program 7873:product topology 7870: 7868: 7867: 7862: 7857: 7856: 7851: 7811:algebraic groups 7800:glide reflection 7797: 7793: 7772:, translations, 7748: 7746: 7745: 7740: 7738: 7730: 7693: 7691: 7690: 7685: 7658: 7654: 7652: 7651: 7646: 7638: 7637: 7612: 7601: 7597: 7593: 7589: 7582: 7574: 7566:orthogonal group 7559: 7557: 7556: 7551: 7549: 7541: 7524: 7518: 7516: 7515: 7510: 7508: 7507: 7499: 7461: 7460: 7454: 7449: 7441: 7439: 7438: 7432: 7424: 7413: 7409: 7405: 7403: 7402: 7397: 7395: 7394: 7386: 7378: 7373: 7365: 7356: 7338: 7336: 7335: 7330: 7328: 7320: 7311: 7307: 7290: 7288: 7287: 7282: 7247: 7239: 7198:Euclidean group 7193: 7185: 7183: 7182: 7177: 7175: 7174: 7169: 7149: 7147: 7146: 7141: 7139: 7132: 7128: 7127: 7126: 7117: 7116: 7098: 7097: 7088: 7087: 7057: 7056: 7041: 7040: 7014: 7013: 7008: 6987: 6985: 6984: 6979: 6977: 6973: 6972: 6964: 6956: 6955: 6949: 6944: 6936: 6931: 6930: 6912: 6907: 6899: 6894: 6893: 6884: 6883: 6863: 6862: 6857: 6828: 6826: 6824: 6823: 6818: 6813: 6812: 6794: 6793: 6764: 6762: 6761: 6756: 6727: 6721: 6719: 6718: 6713: 6711: 6710: 6702: 6694: 6689: 6681: 6664: 6654: 6652: 6651: 6646: 6644: 6636: 6627: 6609: 6607: 6606: 6601: 6599: 6598: 6590: 6585: 6584: 6578: 6573: 6565: 6563: 6562: 6556: 6548: 6543: 6511: 6509: 6508: 6503: 6479: 6477: 6476: 6471: 6469: 6461: 6456: 6448: 6443: 6435: 6426: 6421: 6413: 6403: 6399: 6395: 6393: 6392: 6387: 6385: 6377: 6372: 6364: 6359: 6351: 6342: 6340: 6339: 6334: 6301: 6299: 6298: 6293: 6288: 6284: 6283: 6282: 6264: 6263: 6245: 6244: 6218: 6209: 6183: 6181: 6180: 6175: 6120: 6118: 6117: 6112: 6066: 6064: 6063: 6058: 5956: 5937: 5926: 5922: 5914: 5912: 5911: 5906: 5901: 5900: 5895: 5882: 5863: 5859: 5855: 5844: 5837: 5825:skew coordinates 5789: 5787: 5786: 5781: 5779: 5778: 5770: 5762: 5757: 5749: 5740: 5736: 5730: 5728: 5727: 5722: 5717: 5716: 5694: 5692: 5691: 5686: 5684: 5683: 5668:-th coefficient 5667: 5663: 5661: 5660: 5655: 5653: 5652: 5643: 5642: 5630: 5629: 5620: 5619: 5607: 5606: 5597: 5596: 5574: 5572: 5571: 5566: 5561: 5560: 5548: 5547: 5535: 5534: 5515: 5513: 5512: 5507: 5477: 5475: 5474: 5469: 5464: 5463: 5451: 5450: 5438: 5437: 5418: 5416: 5415: 5410: 5398: 5396: 5395: 5390: 5385: 5384: 5366: 5365: 5349: 5345: 5343: 5342: 5337: 5335: 5327: 5318: 5311: 5309: 5308: 5303: 5301: 5293: 5284: 5280: 5278: 5277: 5272: 5267: 5266: 5248: 5247: 5222: 5214: 5210: 5208: 5207: 5202: 5197: 5189: 5174: 5167: 5165: 5164: 5159: 5154: 5153: 5135: 5134: 5115: 5113: 5112: 5107: 5102: 5101: 5083: 5082: 5059: 5051: 5049: 5048: 5043: 5035: 5034: 5016: 5015: 4993: 4983: 4981: 4980: 4975: 4967: 4966: 4954: 4953: 4937: 4935: 4934: 4929: 4918: 4917: 4894: 4892: 4891: 4886: 4881: 4880: 4862: 4861: 4821: 4805: 4793: 4781: 4770: 4760: 4756: 4749: 4745: 4741: 4735: 4729: 4721: 4719: 4718: 4713: 4711: 4710: 4702: 4694: 4689: 4681: 4672: 4670: 4669: 4664: 4662: 4661: 4653: 4648: 4643: 4635: 4626: 4620: 4614: 4610: 4606: 4600: 4598: 4597: 4592: 4590: 4589: 4580: 4577: 4543: 4540: 4535: 4532: 4527: 4524: 4452: 4448: 4444: 4440: 4429: 4413: 4396: 4385: 4381: 4377: 4373: 4356: 4349: 4341: 4330: 4326: 4310: 4304: 4302: 4301: 4296: 4294: 4290: 4288: 4287: 4279: 4273: 4265: 4259: 4248: 4221: 4219: 4218: 4213: 4211: 4203: 4194: 4190: 4186: 4157: 4155: 4154: 4149: 4147: 4146: 4138: 4127: 4122: 4114: 4109: 4104: 4096: 4085: 4083: 4082: 4077: 4075: 4068: 4067: 4062: 4050: 4042: 4041: 4036: 4024: 4013: 4009: 4004: 3996: 3991: 3986: 3978: 3973: 3968: 3960: 3955: 3950: 3942: 3934: 3930: 3925: 3917: 3912: 3907: 3899: 3891: 3886: 3878: 3873: 3868: 3860: 3855: 3850: 3842: 3837: 3832: 3824: 3816: 3812: 3811: 3805: 3800: 3792: 3787: 3782: 3774: 3772: 3771: 3762: 3761: 3755: 3750: 3742: 3737: 3732: 3724: 3722: 3721: 3709: 3705: 3704: 3696: 3691: 3686: 3678: 3673: 3668: 3660: 3651: 3650: 3645: 3633: 3609: 3607: 3606: 3601: 3596: 3595: 3590: 3578: 3570: 3569: 3564: 3552: 3544: 3543: 3538: 3526: 3512: 3506: 3498:are orthogonal. 3497: 3495: 3494: 3489: 3487: 3486: 3478: 3473: 3468: 3460: 3451: 3449: 3448: 3443: 3441: 3440: 3432: 3427: 3422: 3414: 3394: 3388: 3382: 3364: 3362: 3361: 3356: 3354: 3346: 3335: 3333: 3332: 3327: 3293: 3289: 3287: 3286: 3281: 3279: 3271: 3262: 3258: 3221: 3215: 3209: 3207: 3206: 3201: 3117: 3115: 3114: 3109: 3107: 3096: 3076: 3062:is the distance 3061: 3046: 3044: 3043: 3038: 3036: 3035: 3027: 3019: 3018: 3012: 3007: 2999: 2997: 2996: 2937: 2935: 2934: 2929: 2927: 2919: 2909: 2888: 2886: 2885: 2880: 2875: 2864: 2841: 2830: 2821:will be denoted 2820: 2818: 2817: 2812: 2776: 2759: 2752: 2750: 2749: 2744: 2714: 2712: 2711: 2706: 2704: 2659: 2647: 2639: 2634: 2626: 2604: 2600: 2598: 2597: 2592: 2590: 2582: 2570:Metric structure 2556:Playfair's axiom 2553: 2549: 2547: 2546: 2541: 2536: 2528: 2513: 2509: 2505: 2501: 2495: 2493: 2492: 2487: 2458: 2450: 2446: 2429: 2427: 2426: 2421: 2419: 2418: 2410: 2402: 2401: 2380: 2379: 2373: 2368: 2360: 2349: 2348: 2315: 2311: 2307: 2299: 2295: 2272: 2270: 2269: 2264: 2259: 2258: 2252: 2241: 2240: 2207: 2206: 2191: 2184: 2178: 2176: 2175: 2170: 2168: 2167: 2159: 2151: 2150: 2144: 2133: 2132: 2126: 2121: 2113: 2105: 2100: 2092: 2069: 2068: 2053: 2049: 2039:It follows that 2035: 2031: 2025: 2023: 2022: 2017: 2015: 2014: 2006: 1998: 1997: 1991: 1980: 1979: 1973: 1968: 1960: 1949: 1948: 1915: 1913: 1912: 1907: 1905: 1897: 1888: 1886: 1885: 1880: 1878: 1870: 1858: 1856: 1855: 1850: 1848: 1840: 1831: 1829: 1828: 1823: 1821: 1813: 1802: 1800: 1799: 1794: 1792: 1791: 1785: 1777: 1769: 1768: 1753: 1752: 1743: 1735: 1718: 1716: 1715: 1710: 1705: 1697: 1684: 1682: 1681: 1676: 1674: 1666: 1657: 1653: 1647: 1645: 1644: 1639: 1634: 1633: 1627: 1619: 1611: 1610: 1595: 1594: 1573: 1569: 1562: 1554: 1552: 1551: 1546: 1544: 1536: 1527: 1525: 1524: 1519: 1517: 1509: 1500: 1496: 1494: 1493: 1488: 1483: 1475: 1462: 1456: 1454: 1453: 1448: 1446: 1445: 1437: 1432: 1431: 1404: 1403: 1397: 1392: 1384: 1382: 1381: 1372: 1364: 1353: 1349: 1345: 1326: 1324: 1323: 1318: 1316: 1308: 1299: 1264:Affine structure 1259: 1251: 1249: 1248: 1243: 1241: 1240: 1235: 1222: 1216: 1214: 1213: 1208: 1203: 1202: 1197: 1184: 1180: 1178: 1177: 1172: 1170: 1162: 1145: 1141: 1125: 1123: 1122: 1117: 1115: 1114: 1109: 1074: 1072: 1071: 1066: 1061: 1060: 1052: 1047: 1042: 1034: 1025: 1015: 1011: 997: 990: 975: 971: 967: 958: 956: 955: 950: 891: 881: 877: 842: 840: 839: 834: 832: 824: 811: 808:The elements of 796: 794: 793: 788: 783: 775: 766: 731: 730: 708: 706: 705: 700: 698: 697: 692: 679: 677: 676: 671: 669: 668: 663: 639: 631: 621: 619: 618: 613: 611: 610: 605: 592: 590: 589: 584: 579: 578: 573: 557: 555: 554: 549: 547: 546: 541: 528: 512: 504: 500: 498: 497: 492: 490: 489: 484: 429:reference frames 351: 274: 272: 271: 266: 264: 263: 258: 244: 234: 232: 231: 226: 224: 223: 218: 205: 203: 202: 197: 195: 194: 189: 159:axiomatic theory 97:Euclidean planes 70:Euclidean spaces 64:, but in modern 21: 18:Euclidean spaces 9666: 9665: 9661: 9660: 9659: 9657: 9656: 9655: 9626: 9625: 9624: 9619: 9608: 9587: 9523: 9461: 9415: 9406: 9372:Euclidean space 9355: 9350: 9288:Coxeter, H.S.M. 9281: 9259: 9226: 9198: 9178: 9170: 9166: 9158: 9154: 9146: 9142: 9134: 9127: 9119: 9112: 9104: 9100: 9092: 9088: 9080: 9076: 9068: 9061: 9057: 9052: 9051: 9023: 9020: 9019: 8999: 8995: 8980: 8976: 8968: 8965: 8964: 8960: 8917: 8914: 8913: 8893: 8889: 8872: 8869: 8868: 8849: 8845: 8828: 8825: 8824: 8745: 8742: 8741: 8739: 8735: 8730: 8726: 8721: 8717: 8712: 8674: 8667: 8664: 8658:at this point. 8631:) are spatial. 8594: 8590: 8581: 8577: 8568: 8564: 8555: 8551: 8549: 8546: 8545: 8527:, which is the 8525:Minkowski space 8491: 8401: 8391: 8385: 8350: 8344: 8305: 8299: 8287:elliptic curves 8233:complex numbers 8218: 8212: 8180: 8167:Geometric space 8156: 8152: 8145: 8031: 7996:Tarski's axioms 7930: 7918:locally compact 7852: 7847: 7846: 7844: 7841: 7840: 7825: 7819: 7795: 7791: 7729: 7721: 7718: 7717: 7664: 7661: 7660: 7656: 7630: 7626: 7618: 7615: 7614: 7613:. The isometry 7603: 7599: 7595: 7591: 7587: 7580: 7572: 7540: 7532: 7529: 7528: 7522: 7496: 7495: 7456: 7455: 7442: 7440: 7434: 7433: 7423: 7421: 7418: 7417: 7411: 7407: 7383: 7382: 7366: 7364: 7362: 7359: 7358: 7348: 7341:linear isometry 7319: 7317: 7314: 7313: 7309: 7305: 7299:normal subgroup 7261: 7258: 7257: 7241: 7233: 7230:Euclidean group 7210: 7204:Euclidean group 7202:Main articles: 7200: 7191: 7170: 7165: 7164: 7162: 7159: 7158: 7137: 7136: 7122: 7118: 7112: 7108: 7093: 7089: 7083: 7079: 7072: 7068: 7061: 7052: 7048: 7036: 7032: 7026: 7025: 7015: 7009: 7004: 7003: 6999: 6997: 6994: 6993: 6975: 6974: 6961: 6960: 6951: 6950: 6937: 6935: 6926: 6922: 6900: 6898: 6889: 6885: 6879: 6878: 6871: 6865: 6864: 6858: 6853: 6852: 6845: 6838: 6836: 6833: 6832: 6808: 6804: 6789: 6785: 6774: 6771: 6770: 6768: 6735: 6732: 6731: 6725: 6699: 6698: 6682: 6680: 6672: 6669: 6668: 6656: 6635: 6633: 6630: 6629: 6625: 6622: 6587: 6586: 6580: 6579: 6566: 6564: 6558: 6557: 6547: 6536: 6519: 6516: 6515: 6485: 6482: 6481: 6460: 6447: 6434: 6432: 6429: 6428: 6419: 6415: 6405: 6401: 6397: 6376: 6363: 6350: 6348: 6345: 6344: 6316: 6313: 6312: 6278: 6274: 6259: 6255: 6240: 6236: 6223: 6219: 6207: 6193: 6190: 6189: 6130: 6127: 6126: 6076: 6073: 6072: 5995: 5992: 5991: 5974: 5954: 5928: 5924: 5920: 5896: 5891: 5890: 5888: 5885: 5884: 5880: 5861: 5857: 5853: 5839: 5835: 5809: 5795: 5767: 5766: 5750: 5748: 5746: 5743: 5742: 5738: 5734: 5712: 5708: 5700: 5697: 5696: 5679: 5675: 5673: 5670: 5669: 5665: 5648: 5644: 5638: 5634: 5625: 5621: 5615: 5611: 5602: 5598: 5592: 5588: 5580: 5577: 5576: 5556: 5552: 5543: 5539: 5530: 5526: 5521: 5518: 5517: 5483: 5480: 5479: 5459: 5455: 5446: 5442: 5433: 5429: 5424: 5421: 5420: 5404: 5401: 5400: 5380: 5376: 5361: 5357: 5355: 5352: 5351: 5347: 5326: 5324: 5321: 5320: 5316: 5292: 5290: 5287: 5286: 5282: 5262: 5258: 5243: 5239: 5228: 5225: 5224: 5220: 5212: 5211:and a point of 5188: 5186: 5183: 5182: 5178:Cartesian frame 5172: 5149: 5145: 5130: 5126: 5121: 5118: 5117: 5097: 5093: 5078: 5074: 5069: 5066: 5065: 5057: 5030: 5026: 5011: 5007: 5002: 4999: 4998: 4985: 4962: 4958: 4949: 4945: 4943: 4940: 4939: 4913: 4909: 4904: 4901: 4900: 4876: 4872: 4857: 4853: 4848: 4845: 4844: 4834: 4828: 4811: 4799: 4783: 4775: 4762: 4758: 4754: 4747: 4743: 4737: 4731: 4727: 4699: 4698: 4682: 4680: 4678: 4675: 4674: 4650: 4649: 4636: 4634: 4632: 4629: 4628: 4622: 4616: 4612: 4608: 4604: 4585: 4584: 4576: 4545: 4544: 4539: 4533: and  4531: 4523: 4493: 4492: 4460: 4457: 4456: 4450: 4446: 4442: 4438: 4415: 4401: 4391: 4383: 4379: 4375: 4371: 4354: 4343: 4332: 4328: 4325:[−1, 1] 4324: 4313:principal value 4308: 4283: 4275: 4269: 4261: 4260: 4249: 4247: 4243: 4229: 4226: 4225: 4202: 4200: 4197: 4196: 4192: 4188: 4184: 4170: 4164: 4135: 4134: 4115: 4113: 4097: 4095: 4093: 4090: 4089: 4073: 4072: 4063: 4058: 4057: 4046: 4037: 4032: 4031: 4020: 4011: 4010: 3997: 3995: 3979: 3977: 3961: 3959: 3943: 3941: 3932: 3931: 3918: 3916: 3900: 3898: 3879: 3877: 3861: 3859: 3843: 3841: 3825: 3823: 3814: 3813: 3807: 3806: 3793: 3791: 3775: 3773: 3767: 3766: 3757: 3756: 3743: 3741: 3725: 3723: 3717: 3716: 3707: 3706: 3693: 3692: 3679: 3677: 3661: 3659: 3652: 3646: 3641: 3640: 3629: 3625: 3623: 3620: 3619: 3591: 3586: 3585: 3574: 3565: 3560: 3559: 3548: 3539: 3534: 3533: 3522: 3520: 3517: 3516: 3508: 3502: 3475: 3474: 3461: 3459: 3457: 3454: 3453: 3429: 3428: 3415: 3413: 3411: 3408: 3407: 3406:if the vectors 3390: 3384: 3378: 3345: 3343: 3340: 3339: 3309: 3306: 3305: 3291: 3270: 3268: 3265: 3264: 3260: 3256: 3253: 3245:Main articles: 3243: 3217: 3213: 3135: 3132: 3131: 3103: 3092: 3090: 3087: 3086: 3063: 3057: 3024: 3023: 3014: 3013: 3000: 2998: 2992: 2991: 2968: 2965: 2964: 2951: 2945: 2918: 2916: 2913: 2912: 2907: 2863: 2849: 2846: 2845: 2839: 2822: 2794: 2791: 2790: 2768: 2754: 2726: 2723: 2722: 2702: 2701: 2679: 2661: 2660: 2655: 2648: 2638: 2625: 2621: 2619: 2616: 2615: 2602: 2581: 2579: 2576: 2575: 2572: 2551: 2527: 2519: 2516: 2515: 2511: 2507: 2503: 2502:and a subspace 2499: 2466: 2463: 2462: 2456: 2448: 2444: 2441: 2435: 2407: 2406: 2397: 2396: 2375: 2374: 2361: 2359: 2344: 2343: 2323: 2320: 2319: 2313: 2309: 2301: 2297: 2293: 2254: 2253: 2248: 2236: 2235: 2202: 2201: 2199: 2196: 2195: 2189: 2182: 2156: 2155: 2146: 2145: 2140: 2128: 2127: 2114: 2112: 2093: 2091: 2064: 2063: 2061: 2058: 2057: 2051: 2047: 2033: 2029: 2003: 2002: 1993: 1992: 1987: 1975: 1974: 1961: 1959: 1944: 1943: 1941: 1938: 1937: 1928: 1926:Line (geometry) 1922: 1896: 1894: 1891: 1890: 1869: 1867: 1864: 1863: 1839: 1837: 1834: 1833: 1812: 1810: 1807: 1806: 1787: 1786: 1776: 1764: 1763: 1748: 1747: 1734: 1726: 1723: 1722: 1696: 1694: 1691: 1690: 1687:linear subspace 1665: 1663: 1660: 1659: 1655: 1651: 1650:Conversely, if 1629: 1628: 1618: 1606: 1605: 1590: 1589: 1581: 1578: 1577: 1571: 1567: 1560: 1535: 1533: 1530: 1529: 1508: 1506: 1503: 1502: 1498: 1474: 1472: 1469: 1468: 1465:linear subspace 1460: 1434: 1433: 1427: 1426: 1399: 1398: 1385: 1383: 1377: 1376: 1363: 1361: 1358: 1357: 1351: 1347: 1343: 1340:affine subspace 1307: 1305: 1302: 1301: 1297: 1294: 1292:Flat (geometry) 1288: 1272: 1266: 1257: 1236: 1231: 1230: 1228: 1225: 1224: 1220: 1198: 1193: 1192: 1190: 1187: 1186: 1182: 1161: 1159: 1156: 1155: 1143: 1139: 1110: 1105: 1104: 1102: 1099: 1098: 1091: 1049: 1048: 1035: 1033: 1031: 1028: 1027: 1017: 1013: 999: 995: 980: 973: 969: 965: 899: 896: 895: 883: 879: 875: 823: 821: 818: 817: 809: 774: 772: 769: 768: 764: 746:Euclidean space 728: 727: 723: 711:coordinate-free 693: 688: 687: 685: 682: 681: 664: 659: 658: 656: 653: 652: 637: 629: 606: 601: 600: 598: 595: 594: 574: 569: 568: 566: 563: 562: 542: 537: 536: 534: 531: 530: 526: 510: 502: 485: 480: 479: 477: 474: 473: 433:units of length 378: 358:Platonic solids 349: 346:Ludwig Schläfli 290: 285: 259: 254: 253: 251: 248: 247: 242: 219: 214: 213: 211: 208: 207: 190: 185: 184: 182: 179: 178: 112:Greek geometers 93:Euclidean lines 39:Euclidean space 28: 23: 22: 15: 12: 11: 5: 9664: 9654: 9653: 9648: 9643: 9641:Linear algebra 9638: 9621: 9620: 9613: 9610: 9609: 9607: 9606: 9601: 9595: 9593: 9589: 9588: 9586: 9585: 9577: 9572: 9567: 9562: 9557: 9552: 9547: 9542: 9537: 9531: 9529: 9525: 9524: 9522: 9521: 9516: 9511: 9509:Cross-polytope 9506: 9501: 9496: 9494:Hyperrectangle 9491: 9486: 9481: 9475: 9473: 9463: 9462: 9460: 9459: 9454: 9449: 9444: 9439: 9434: 9429: 9423: 9421: 9417: 9416: 9409: 9407: 9405: 9404: 9399: 9394: 9389: 9384: 9379: 9374: 9369: 9363: 9361: 9357: 9356: 9349: 9348: 9341: 9334: 9326: 9320: 9319: 9301: 9284: 9279: 9267:Berger, Marcel 9263: 9257: 9237: 9224: 9201: 9196: 9177: 9176: 9164: 9152: 9140: 9125: 9123:, Section 9.1. 9110: 9098: 9086: 9074: 9058: 9056: 9053: 9050: 9049: 9036: 9033: 9030: 9027: 9007: 9002: 8998: 8994: 8991: 8988: 8983: 8979: 8975: 8972: 8948: 8945: 8942: 8939: 8936: 8933: 8930: 8927: 8924: 8921: 8901: 8896: 8892: 8888: 8885: 8882: 8879: 8876: 8857: 8852: 8848: 8844: 8841: 8838: 8835: 8832: 8812: 8809: 8806: 8803: 8800: 8797: 8794: 8791: 8788: 8785: 8782: 8779: 8776: 8773: 8770: 8767: 8764: 8761: 8758: 8755: 8752: 8749: 8733: 8724: 8714: 8713: 8711: 8708: 8707: 8706: 8700:Position space 8697: 8680: 8679: 8663: 8660: 8648:tangent spaces 8638:into account, 8602: 8597: 8593: 8589: 8584: 8580: 8576: 8571: 8567: 8563: 8558: 8554: 8541:quadratic form 8514:quadratic form 8511:non-degenerate 8490: 8487: 8456:straight lines 8448:tangent spaces 8387:Main article: 8384: 8381: 8346:Main article: 8343: 8340: 8301:Main article: 8298: 8295: 8214:Main article: 8211: 8208: 8182: 8181: 8159: 8157: 8150: 8144: 8141: 8125:elliptic space 8105:Tangent spaces 8035:ancient Greeks 8030: 8027: 7980:G. D. Birkhoff 7966:, inspired by 7929: 7926: 7860: 7855: 7850: 7821:Main article: 7818: 7815: 7736: 7733: 7728: 7725: 7683: 7680: 7677: 7674: 7671: 7668: 7644: 7641: 7636: 7633: 7629: 7625: 7622: 7547: 7544: 7539: 7536: 7502: 7494: 7491: 7488: 7485: 7482: 7479: 7476: 7473: 7470: 7467: 7464: 7459: 7452: 7448: 7445: 7437: 7430: 7427: 7389: 7381: 7376: 7372: 7369: 7326: 7323: 7280: 7277: 7274: 7271: 7268: 7265: 7228:), called the 7199: 7196: 7173: 7168: 7135: 7131: 7125: 7121: 7115: 7111: 7107: 7104: 7101: 7096: 7092: 7086: 7082: 7078: 7075: 7071: 7067: 7064: 7062: 7060: 7055: 7051: 7047: 7044: 7039: 7035: 7031: 7028: 7027: 7024: 7021: 7018: 7016: 7012: 7007: 7002: 7001: 6967: 6959: 6954: 6947: 6943: 6940: 6934: 6929: 6925: 6921: 6918: 6915: 6910: 6906: 6903: 6897: 6892: 6888: 6882: 6877: 6874: 6872: 6870: 6867: 6866: 6861: 6856: 6851: 6848: 6846: 6844: 6841: 6840: 6816: 6811: 6807: 6803: 6800: 6797: 6792: 6788: 6784: 6781: 6778: 6754: 6751: 6748: 6745: 6742: 6739: 6705: 6697: 6692: 6688: 6685: 6679: 6676: 6642: 6639: 6621: 6618: 6593: 6583: 6576: 6572: 6569: 6561: 6554: 6551: 6546: 6542: 6539: 6535: 6532: 6529: 6526: 6523: 6501: 6498: 6495: 6492: 6489: 6467: 6464: 6459: 6454: 6451: 6446: 6441: 6438: 6383: 6380: 6375: 6370: 6367: 6362: 6357: 6354: 6332: 6329: 6326: 6323: 6320: 6291: 6287: 6281: 6277: 6273: 6270: 6267: 6262: 6258: 6254: 6251: 6248: 6243: 6239: 6235: 6232: 6229: 6226: 6222: 6215: 6212: 6206: 6203: 6200: 6197: 6173: 6170: 6167: 6164: 6161: 6158: 6155: 6152: 6149: 6146: 6143: 6140: 6137: 6134: 6110: 6107: 6104: 6101: 6098: 6095: 6092: 6089: 6086: 6083: 6080: 6056: 6053: 6050: 6047: 6044: 6041: 6038: 6035: 6032: 6029: 6026: 6023: 6020: 6017: 6014: 6011: 6008: 6005: 6002: 5999: 5973: 5970: 5904: 5899: 5894: 5870:diffeomorphism 5805:Main article: 5794: 5791: 5773: 5765: 5760: 5756: 5753: 5720: 5715: 5711: 5707: 5704: 5682: 5678: 5651: 5647: 5641: 5637: 5633: 5628: 5624: 5618: 5614: 5610: 5605: 5601: 5595: 5591: 5587: 5584: 5564: 5559: 5555: 5551: 5546: 5542: 5538: 5533: 5529: 5525: 5505: 5502: 5499: 5496: 5493: 5490: 5487: 5467: 5462: 5458: 5454: 5449: 5445: 5441: 5436: 5432: 5428: 5408: 5388: 5383: 5379: 5375: 5372: 5369: 5364: 5360: 5333: 5330: 5299: 5296: 5270: 5265: 5261: 5257: 5254: 5251: 5246: 5242: 5238: 5235: 5232: 5200: 5195: 5192: 5157: 5152: 5148: 5144: 5141: 5138: 5133: 5129: 5125: 5105: 5100: 5096: 5092: 5089: 5086: 5081: 5077: 5073: 5041: 5038: 5033: 5029: 5025: 5022: 5019: 5014: 5010: 5006: 4973: 4970: 4965: 4961: 4957: 4952: 4948: 4927: 4924: 4921: 4916: 4912: 4908: 4884: 4879: 4875: 4871: 4868: 4865: 4860: 4856: 4852: 4827: 4824: 4808:oriented angle 4705: 4697: 4692: 4688: 4685: 4656: 4646: 4642: 4639: 4588: 4583: 4574: 4571: 4568: 4565: 4562: 4559: 4556: 4553: 4550: 4547: 4546: 4538: 4530: 4520: 4517: 4514: 4511: 4508: 4505: 4502: 4499: 4498: 4496: 4491: 4488: 4485: 4482: 4479: 4476: 4473: 4470: 4467: 4464: 4367:oriented angle 4293: 4286: 4282: 4278: 4272: 4268: 4264: 4258: 4255: 4252: 4246: 4242: 4239: 4236: 4233: 4209: 4206: 4166:Main article: 4163: 4160: 4141: 4133: 4130: 4125: 4121: 4118: 4112: 4107: 4103: 4100: 4071: 4066: 4061: 4056: 4053: 4049: 4045: 4040: 4035: 4030: 4027: 4023: 4019: 4016: 4014: 4012: 4007: 4003: 4000: 3994: 3989: 3985: 3982: 3976: 3971: 3967: 3964: 3958: 3953: 3949: 3946: 3940: 3937: 3935: 3933: 3928: 3924: 3921: 3915: 3910: 3906: 3903: 3897: 3894: 3889: 3885: 3882: 3876: 3871: 3867: 3864: 3858: 3853: 3849: 3846: 3840: 3835: 3831: 3828: 3822: 3819: 3817: 3815: 3810: 3803: 3799: 3796: 3790: 3785: 3781: 3778: 3770: 3765: 3760: 3753: 3749: 3746: 3740: 3735: 3731: 3728: 3720: 3715: 3712: 3710: 3708: 3699: 3689: 3685: 3682: 3676: 3671: 3667: 3664: 3658: 3655: 3653: 3649: 3644: 3639: 3636: 3632: 3628: 3627: 3599: 3594: 3589: 3584: 3581: 3577: 3573: 3568: 3563: 3558: 3555: 3551: 3547: 3542: 3537: 3532: 3529: 3525: 3481: 3471: 3467: 3464: 3435: 3425: 3421: 3418: 3352: 3349: 3325: 3322: 3319: 3316: 3313: 3277: 3274: 3242: 3239: 3199: 3196: 3193: 3190: 3187: 3184: 3181: 3178: 3175: 3172: 3169: 3166: 3163: 3160: 3157: 3154: 3151: 3148: 3145: 3142: 3139: 3106: 3102: 3099: 3095: 3030: 3022: 3017: 3010: 3006: 3003: 2995: 2990: 2987: 2984: 2981: 2978: 2975: 2972: 2947:Main article: 2944: 2941: 2925: 2922: 2899:properties of 2878: 2873: 2870: 2867: 2862: 2859: 2856: 2853: 2836:Euclidean norm 2810: 2807: 2804: 2801: 2798: 2742: 2739: 2736: 2733: 2730: 2700: 2697: 2694: 2691: 2688: 2685: 2682: 2680: 2678: 2675: 2672: 2669: 2666: 2663: 2662: 2658: 2654: 2651: 2649: 2645: 2642: 2637: 2632: 2629: 2624: 2623: 2588: 2585: 2571: 2568: 2539: 2534: 2531: 2526: 2523: 2498:Given a point 2485: 2482: 2479: 2476: 2473: 2470: 2443:Two subspaces 2437:Main article: 2434: 2431: 2413: 2405: 2400: 2395: 2392: 2389: 2386: 2383: 2378: 2371: 2367: 2364: 2358: 2355: 2352: 2347: 2342: 2339: 2336: 2333: 2330: 2327: 2262: 2257: 2251: 2247: 2244: 2239: 2234: 2231: 2228: 2225: 2222: 2219: 2216: 2213: 2210: 2205: 2162: 2154: 2149: 2143: 2139: 2136: 2131: 2124: 2120: 2117: 2111: 2108: 2103: 2099: 2096: 2090: 2087: 2084: 2081: 2078: 2075: 2072: 2067: 2009: 2001: 1996: 1990: 1986: 1983: 1978: 1971: 1967: 1964: 1958: 1955: 1952: 1947: 1924:Main article: 1921: 1918: 1903: 1900: 1876: 1873: 1846: 1843: 1819: 1816: 1790: 1783: 1780: 1775: 1772: 1767: 1762: 1759: 1756: 1751: 1746: 1741: 1738: 1733: 1730: 1708: 1703: 1700: 1672: 1669: 1654:is a point of 1637: 1632: 1625: 1622: 1617: 1614: 1609: 1604: 1601: 1598: 1593: 1588: 1585: 1570:is a point of 1542: 1539: 1515: 1512: 1486: 1481: 1478: 1440: 1430: 1425: 1422: 1419: 1416: 1413: 1410: 1407: 1402: 1395: 1391: 1388: 1380: 1375: 1370: 1367: 1314: 1311: 1290:Main article: 1287: 1284: 1268:Main article: 1265: 1262: 1239: 1234: 1206: 1201: 1196: 1168: 1165: 1113: 1108: 1090: 1087: 1064: 1055: 1045: 1041: 1038: 1012:. This vector 948: 945: 942: 939: 936: 933: 930: 927: 924: 921: 918: 915: 912: 909: 906: 903: 830: 827: 786: 781: 778: 722: 719: 696: 691: 667: 662: 609: 604: 582: 577: 572: 545: 540: 488: 483: 377: 374: 327:René Descartes 294:ancient Greeks 289: 286: 284: 281: 262: 257: 222: 217: 193: 188: 167:linear algebra 118:mathematician 47:physical space 26: 9: 6: 4: 3: 2: 9663: 9652: 9649: 9647: 9644: 9642: 9639: 9637: 9634: 9633: 9631: 9618: 9617: 9611: 9605: 9602: 9600: 9597: 9596: 9594: 9590: 9584: 9582: 9578: 9576: 9573: 9571: 9568: 9566: 9563: 9561: 9558: 9556: 9553: 9551: 9548: 9546: 9543: 9541: 9538: 9536: 9533: 9532: 9530: 9526: 9520: 9517: 9515: 9512: 9510: 9507: 9505: 9502: 9500: 9499:Demihypercube 9497: 9495: 9492: 9490: 9487: 9485: 9482: 9480: 9477: 9476: 9474: 9472: 9468: 9464: 9458: 9455: 9453: 9450: 9448: 9445: 9443: 9440: 9438: 9435: 9433: 9430: 9428: 9425: 9424: 9422: 9418: 9413: 9403: 9400: 9398: 9395: 9393: 9390: 9388: 9385: 9383: 9380: 9378: 9375: 9373: 9370: 9368: 9365: 9364: 9362: 9358: 9354: 9347: 9342: 9340: 9335: 9333: 9328: 9327: 9324: 9317: 9313: 9312: 9307: 9302: 9299: 9295: 9294: 9289: 9285: 9282: 9280:3-540-11658-3 9276: 9272: 9268: 9264: 9260: 9258:0-486-20630-0 9254: 9249: 9248: 9242: 9238: 9235: 9231: 9227: 9225:0-471-60839-4 9221: 9217: 9213: 9209: 9208: 9202: 9199: 9197:0-471-84819-0 9193: 9189: 9185: 9180: 9179: 9173: 9168: 9161: 9156: 9149: 9144: 9137: 9132: 9130: 9122: 9117: 9115: 9107: 9102: 9095: 9090: 9083: 9078: 9071: 9066: 9064: 9059: 9034: 9031: 9028: 9025: 9005: 9000: 8992: 8986: 8981: 8973: 8946: 8940: 8934: 8931: 8925: 8919: 8899: 8894: 8883: 8877: 8855: 8850: 8839: 8833: 8810: 8807: 8801: 8795: 8792: 8789: 8783: 8777: 8774: 8771: 8765: 8762: 8759: 8756: 8753: 8747: 8737: 8728: 8719: 8715: 8705: 8701: 8698: 8696: 8692: 8689: 8685: 8684:Hilbert space 8682: 8681: 8677: 8671: 8666: 8659: 8657: 8653: 8649: 8645: 8641: 8637: 8632: 8630: 8626: 8622: 8618: 8613: 8600: 8595: 8591: 8587: 8582: 8578: 8574: 8569: 8565: 8561: 8556: 8552: 8543: 8542: 8538: 8534: 8530: 8526: 8521: 8519: 8516:(that may be 8515: 8512: 8508: 8504: 8500: 8496: 8495:inner product 8486: 8484: 8480: 8476: 8472: 8468: 8463: 8461: 8457: 8454:. Generally, 8453: 8449: 8445: 8440: 8438: 8434: 8430: 8426: 8422: 8418: 8414: 8410: 8406: 8400: 8396: 8390: 8383:Curved spaces 8380: 8378: 8374: 8370: 8366: 8362: 8358: 8354: 8349: 8339: 8337: 8333: 8328: 8326: 8322: 8318: 8314: 8310: 8304: 8294: 8292: 8288: 8284: 8283:finite fields 8279: 8277: 8273: 8269: 8268:number theory 8265: 8261: 8256: 8254: 8250: 8246: 8242: 8238: 8234: 8229: 8227: 8223: 8217: 8207: 8205: 8201: 8197: 8193: 8189: 8178: 8173: 8169: 8168: 8163: 8158: 8149: 8148: 8140: 8138: 8134: 8130: 8126: 8122: 8118: 8114: 8110: 8106: 8102: 8097: 8095: 8091: 8087: 8082: 8080: 8076: 8072: 8068: 8064: 8060: 8056: 8052: 8048: 8044: 8040: 8036: 8026: 8023: 8019: 8015: 8010: 8006: 8005: 7999: 7997: 7993: 7989: 7985: 7984:Alfred Tarski 7981: 7977: 7973: 7969: 7965: 7961: 7960:David Hilbert 7956: 7954: 7950: 7946: 7941: 7939: 7935: 7925: 7923: 7919: 7915: 7910: 7908: 7904: 7900: 7896: 7891: 7889: 7885: 7881: 7876: 7874: 7858: 7853: 7838: 7834: 7831:, and thus a 7830: 7824: 7814: 7812: 7808: 7803: 7801: 7788: 7786: 7781: 7779: 7778:screw motions 7775: 7771: 7766: 7764: 7763:displacements 7760: 7759:rigid motions 7756: 7752: 7734: 7731: 7723: 7715: 7711: 7707: 7702: 7701: 7699: 7681: 7678: 7675: 7672: 7669: 7666: 7642: 7639: 7634: 7631: 7627: 7623: 7620: 7610: 7606: 7584: 7578: 7569: 7567: 7563: 7545: 7542: 7534: 7525: 7519: 7492: 7486: 7480: 7477: 7471: 7465: 7462: 7450: 7446: 7443: 7428: 7425: 7415: 7379: 7374: 7370: 7367: 7355: 7351: 7346: 7342: 7324: 7321: 7302: 7300: 7296: 7291: 7278: 7275: 7272: 7269: 7263: 7255: 7254: 7249: 7245: 7237: 7231: 7227: 7223: 7219: 7215: 7209: 7205: 7195: 7189: 7171: 7155: 7154: 7150: 7133: 7129: 7123: 7119: 7113: 7109: 7105: 7102: 7099: 7094: 7090: 7084: 7080: 7076: 7073: 7069: 7063: 7053: 7049: 7045: 7042: 7037: 7033: 7022: 7017: 7010: 6991: 6988: 6957: 6945: 6941: 6938: 6932: 6927: 6923: 6919: 6916: 6913: 6908: 6904: 6901: 6895: 6890: 6886: 6873: 6868: 6859: 6847: 6842: 6830: 6809: 6805: 6801: 6798: 6795: 6790: 6786: 6782: 6779: 6765: 6752: 6749: 6746: 6743: 6737: 6729: 6722: 6695: 6690: 6686: 6683: 6674: 6666: 6663: 6659: 6640: 6637: 6617: 6613: 6610: 6574: 6570: 6567: 6552: 6549: 6544: 6540: 6537: 6533: 6527: 6521: 6513: 6499: 6493: 6490: 6487: 6465: 6462: 6452: 6449: 6444: 6439: 6436: 6425: 6418: 6412: 6408: 6381: 6378: 6368: 6365: 6360: 6355: 6352: 6330: 6324: 6321: 6318: 6309: 6307: 6302: 6289: 6285: 6279: 6271: 6265: 6260: 6252: 6246: 6241: 6233: 6230: 6227: 6220: 6213: 6210: 6204: 6201: 6198: 6195: 6187: 6184: 6171: 6168: 6165: 6162: 6159: 6153: 6147: 6144: 6138: 6132: 6124: 6121: 6108: 6102: 6096: 6087: 6081: 6070: 6067: 6054: 6048: 6045: 6042: 6036: 6033: 6024: 6018: 6015: 6009: 6003: 5997: 5989: 5987: 5983: 5982:metric spaces 5979: 5969: 5967: 5962: 5960: 5951: 5949: 5945: 5941: 5935: 5931: 5918: 5902: 5897: 5878: 5875: 5871: 5867: 5866:homeomorphism 5856:of dimension 5850: 5848: 5842: 5833: 5828: 5826: 5822: 5818: 5814: 5808: 5799: 5790: 5763: 5758: 5754: 5751: 5731: 5718: 5713: 5709: 5705: 5702: 5680: 5676: 5649: 5645: 5639: 5635: 5631: 5626: 5622: 5616: 5612: 5608: 5603: 5599: 5593: 5589: 5585: 5582: 5557: 5553: 5549: 5544: 5540: 5536: 5531: 5527: 5500: 5497: 5494: 5491: 5488: 5460: 5456: 5452: 5447: 5443: 5439: 5434: 5430: 5406: 5386: 5381: 5377: 5373: 5370: 5367: 5362: 5358: 5331: 5328: 5313: 5297: 5294: 5263: 5259: 5255: 5252: 5249: 5244: 5240: 5236: 5233: 5218: 5215:, called the 5198: 5193: 5190: 5180: 5179: 5169: 5150: 5146: 5142: 5139: 5136: 5131: 5127: 5098: 5094: 5090: 5087: 5084: 5079: 5075: 5063: 5055: 5039: 5031: 5027: 5023: 5020: 5017: 5012: 5008: 4997: 4992: 4988: 4971: 4968: 4963: 4959: 4955: 4950: 4946: 4925: 4922: 4914: 4910: 4898: 4877: 4873: 4869: 4866: 4863: 4858: 4854: 4843: 4839: 4833: 4823: 4819: 4815: 4809: 4803: 4797: 4791: 4787: 4779: 4774: 4769: 4765: 4751: 4740: 4734: 4725: 4695: 4690: 4686: 4683: 4644: 4640: 4637: 4625: 4619: 4601: 4581: 4569: 4566: 4563: 4557: 4554: 4551: 4548: 4536: 4528: 4515: 4512: 4509: 4503: 4500: 4494: 4489: 4483: 4480: 4477: 4474: 4471: 4465: 4462: 4454: 4436: 4431: 4427: 4423: 4419: 4412: 4408: 4404: 4400: 4395: 4389: 4369: 4368: 4363: 4358: 4351: 4347: 4340: 4336: 4331:is real, and 4322: 4319:function. By 4318: 4314: 4305: 4291: 4280: 4266: 4256: 4253: 4250: 4244: 4240: 4237: 4234: 4231: 4223: 4207: 4204: 4183: 4174: 4169: 4159: 4131: 4128: 4123: 4119: 4116: 4110: 4105: 4101: 4098: 4086: 4069: 4064: 4054: 4051: 4043: 4038: 4028: 4025: 4017: 4015: 4005: 4001: 3998: 3992: 3987: 3983: 3980: 3974: 3969: 3965: 3962: 3956: 3951: 3947: 3944: 3938: 3936: 3926: 3922: 3919: 3913: 3908: 3904: 3901: 3895: 3892: 3887: 3883: 3880: 3874: 3869: 3865: 3862: 3856: 3851: 3847: 3844: 3838: 3833: 3829: 3826: 3820: 3818: 3801: 3797: 3794: 3788: 3783: 3779: 3776: 3763: 3751: 3747: 3744: 3738: 3733: 3729: 3726: 3713: 3711: 3687: 3683: 3680: 3674: 3669: 3665: 3662: 3656: 3654: 3647: 3637: 3634: 3617: 3615: 3610: 3597: 3592: 3582: 3579: 3571: 3566: 3556: 3553: 3545: 3540: 3530: 3527: 3514: 3511: 3505: 3499: 3469: 3465: 3462: 3423: 3419: 3416: 3405: 3404: 3398: 3397:perpendicular 3393: 3387: 3381: 3377:Two segments 3375: 3373: 3372:perpendicular 3367: 3350: 3347: 3336: 3323: 3320: 3317: 3314: 3311: 3303: 3301: 3297: 3296:perpendicular 3275: 3272: 3252: 3251:Orthogonality 3248: 3247:Perpendicular 3241:Orthogonality 3238: 3236: 3231: 3229: 3225: 3220: 3210: 3197: 3191: 3188: 3185: 3179: 3176: 3170: 3167: 3164: 3158: 3155: 3149: 3146: 3143: 3137: 3129: 3128: 3124: 3119: 3100: 3097: 3084: 3080: 3074: 3070: 3066: 3060: 3056: 3052: 3047: 3020: 3008: 3004: 3001: 2988: 2982: 2979: 2976: 2970: 2962: 2960: 2956: 2950: 2940: 2939: 2923: 2920: 2906: 2902: 2898: 2894: 2889: 2876: 2871: 2868: 2865: 2860: 2854: 2843: 2837: 2832: 2829: 2825: 2805: 2802: 2799: 2788: 2784: 2780: 2775: 2771: 2766: 2761: 2757: 2737: 2734: 2731: 2720: 2715: 2695: 2692: 2689: 2681: 2673: 2670: 2667: 2650: 2643: 2640: 2635: 2630: 2627: 2613: 2612: 2608: 2586: 2583: 2567: 2565: 2562: 2559: 2557: 2537: 2532: 2529: 2524: 2521: 2496: 2483: 2480: 2477: 2474: 2471: 2468: 2460: 2454: 2440: 2430: 2403: 2393: 2390: 2387: 2384: 2381: 2369: 2365: 2362: 2356: 2353: 2350: 2340: 2337: 2334: 2331: 2328: 2325: 2317: 2305: 2291: 2287: 2286: 2280: 2278: 2273: 2260: 2245: 2242: 2232: 2229: 2226: 2223: 2217: 2214: 2211: 2193: 2186: 2179: 2152: 2137: 2134: 2122: 2118: 2115: 2109: 2106: 2101: 2097: 2094: 2085: 2082: 2079: 2073: 2070: 2055: 2044: 2042: 2037: 2026: 1999: 1984: 1981: 1969: 1965: 1962: 1956: 1953: 1950: 1935: 1933: 1927: 1917: 1901: 1898: 1874: 1871: 1860: 1844: 1841: 1817: 1814: 1803: 1781: 1778: 1773: 1770: 1760: 1757: 1754: 1744: 1739: 1736: 1731: 1728: 1720: 1706: 1701: 1698: 1688: 1670: 1667: 1648: 1635: 1623: 1620: 1615: 1612: 1602: 1599: 1596: 1586: 1583: 1575: 1564: 1558: 1540: 1537: 1513: 1510: 1484: 1479: 1476: 1466: 1457: 1423: 1420: 1417: 1414: 1411: 1408: 1405: 1393: 1389: 1386: 1373: 1368: 1365: 1355: 1341: 1337: 1333: 1328: 1312: 1309: 1293: 1283: 1281: 1277: 1271: 1261: 1256:of dimension 1255: 1237: 1217: 1204: 1199: 1166: 1163: 1153: 1149: 1142:of dimension 1137: 1133: 1132:inner product 1129: 1111: 1095: 1086: 1084: 1080: 1075: 1062: 1043: 1039: 1036: 1024: 1020: 1010: 1006: 1002: 994: 988: 984: 977: 963: 959: 946: 943: 940: 934: 931: 928: 922: 916: 913: 910: 904: 901: 893: 890: 886: 872: 870: 866: 862: 858: 854: 853: 848: 847: 828: 825: 815: 806: 804: 800: 784: 779: 776: 761: 759: 755: 751: 747: 742: 740: 736: 732: 718: 716: 712: 694: 665: 645: 641: 635: 628:of dimension 627: 626: 607: 580: 575: 559: 543: 524: 520: 516: 508: 486: 470: 468: 464: 460: 459:inner product 456: 452: 449: 444: 442: 438: 434: 430: 426: 422: 417: 415: 411: 407: 403: 399: 395: 391: 387: 383: 382:set of points 373: 370: 369:vector spaces 366: 361: 359: 355: 347: 342: 340: 336: 332: 328: 323: 321: 317: 313: 308: 307: 302: 301: 295: 280: 278: 260: 246: 238: 220: 191: 176: 171: 168: 164: 163:vector spaces 160: 156: 151: 149: 145: 144:straight line 141: 140: 135: 131: 130: 125: 121: 117: 116:ancient Greek 113: 108: 106: 102: 98: 94: 90: 86: 84: 78: 75: 71: 67: 63: 59: 56:, it was the 55: 54: 48: 44: 40: 32: 19: 9614: 9580: 9519:Hyperpyramid 9484:Hypersurface 9377:Affine space 9371: 9367:Vector space 9309: 9297: 9292: 9270: 9246: 9205: 9183: 9167: 9155: 9143: 9138:, Chapter 9. 9106:Coxeter 1973 9101: 9089: 9077: 8736: 8727: 8718: 8633: 8628: 8624: 8620: 8616: 8614: 8544: 8522: 8492: 8464: 8441: 8417:homeomorphic 8413:neighborhood 8402: 8389:Curved space 8352: 8351: 8329: 8325:vector space 8321:vector lines 8306: 8291:cryptography 8280: 8276:Fermat curve 8257: 8230: 8219: 8216:Affine space 8210:Affine space 8185: 8177:(March 2023) 8176: 8165: 8132: 8098: 8083: 8059:architecture 8032: 8021: 8002: 8000: 7988:real numbers 7976:real numbers 7957: 7942: 7931: 7911: 7899:homeomorphic 7892: 7877: 7829:metric space 7826: 7804: 7789: 7782: 7767: 7762: 7758: 7754: 7750: 7703: 7695: 7608: 7604: 7590:be a point, 7585: 7570: 7526: 7520: 7416: 7353: 7349: 7340: 7303: 7294: 7292: 7256: 7253:translations 7250: 7243: 7235: 7229: 7221: 7217: 7213: 7211: 7187: 7156: 7152: 7151: 6992: 6989: 6831: 6766: 6730: 6723: 6667: 6661: 6657: 6623: 6614: 6611: 6514: 6423: 6416: 6410: 6406: 6311:An isometry 6310: 6303: 6188: 6185: 6125: 6122: 6071: 6068: 5990: 5980:between two 5975: 5963: 5959:antimeridian 5952: 5933: 5929: 5916: 5851: 5840: 5838:is a set of 5832:affine basis 5829: 5824: 5817:affine frame 5813:affine space 5810: 5732: 5314: 5216: 5176: 5170: 5062:linear spans 4990: 4986: 4897:unit vectors 4835: 4817: 4813: 4807: 4801: 4795: 4789: 4785: 4777: 4767: 4763: 4752: 4738: 4732: 4623: 4617: 4602: 4455: 4432: 4425: 4421: 4417: 4410: 4406: 4402: 4399:reflex angle 4393: 4365: 4359: 4352: 4345: 4338: 4334: 4327:. Therefore 4306: 4224: 4181: 4179: 4087: 3618: 3612:This is the 3611: 3515: 3509: 3503: 3500: 3400: 3396: 3391: 3385: 3379: 3376: 3371: 3368: 3337: 3304: 3299: 3295: 3254: 3232: 3227: 3218: 3211: 3130: 3120: 3082: 3078: 3072: 3068: 3064: 3058: 3050: 3048: 2963: 2958: 2954: 2952: 2910: 2904: 2890: 2844: 2838:of a vector 2835: 2833: 2827: 2823: 2773: 2769: 2767:and denoted 2764: 2762: 2755: 2716: 2614: 2573: 2566: 2563: 2560: 2497: 2461: 2452: 2442: 2318: 2303: 2289: 2288:, or simply 2285:line segment 2283: 2281: 2274: 2194: 2187: 2180: 2056: 2045: 2040: 2038: 2027: 1936: 1931: 1929: 1861: 1804: 1721: 1649: 1576: 1565: 1556: 1458: 1356: 1346:is a subset 1339: 1335: 1331: 1329: 1295: 1276:affine space 1273: 1270:Affine space 1253: 1218: 1147: 1096: 1092: 1076: 1022: 1018: 1008: 1004: 1000: 986: 982: 978: 961: 960: 894: 888: 884: 873: 857:translations 856: 852:free vectors 850: 844: 813: 807: 798: 762: 757: 750:affine space 745: 743: 739:real numbers 726: 724: 714: 710: 680:instead of 650: 633: 632:, or simply 624: 623: 560: 514: 471: 463:affine space 454: 445: 418: 379: 362: 343: 339:real numbers 324: 304: 299: 291: 172: 152: 137: 127: 123: 109: 88: 82: 80: 76: 69: 52: 38: 37: 9604:Codimension 9583:-dimensions 9504:Hypersphere 9387:Free module 9160:Berger 1987 9148:Anton (1987 9136:Berger 1987 9121:Berger 1987 9094:Berger 1987 8475:orthodromes 8421:open subset 8200:consistency 7945:Felix Klein 7785:reflections 7357:the vector 7226:composition 6724:which maps 6512:defined by 5948:cylindrical 5919:of a point 5917:coordinates 5877:open subset 5168:are equal. 3403:right angle 2897:topological 2783:dot product 2765:dot product 2514:, which is 2433:Parallelism 1128:dot product 1016:is denoted 964:The second 878:on a point 861:translation 843:are called 812:are called 715:origin-free 523:isomorphism 507:dot product 467:parallelism 425:abstraction 410:reflections 390:translation 329:introduced 277:dot product 66:mathematics 9630:Categories 9599:Hyperspace 9479:Hyperplane 9271:Geometry I 9172:Artin 1988 9055:References 8693:, used in 8529:space-time 8518:indefinite 8479:navigation 8369:consistent 8071:navigation 8067:topography 8045:, such as 8033:Since the 8014:congruence 8009:Emil Artin 7949:symmetries 7807:Lie groups 7710:handedness 7414:, one has 7345:linear map 5972:Isometries 4830:See also: 4724:half-lines 4435:multiplied 3300:orthogonal 2316:; that is 1354:such that 1136:isomorphic 998:such that 435:and other 312:postulates 283:Definition 175:isomorphic 139:postulates 81:Euclidean 68:there are 9489:Hypercube 9467:Polytopes 9447:Minkowski 9442:Hausdorff 9437:Inductive 9402:Spacetime 9353:Dimension 9316:EMS Press 9290:(1973) . 9243:(1960) . 9082:Ball 1960 9029:⋅ 8997:‖ 8990:‖ 8978:‖ 8971:‖ 8932:⋅ 8891:‖ 8875:‖ 8847:‖ 8831:‖ 8793:μ 8790:− 8775:λ 8772:− 8763:μ 8754:λ 8710:Footnotes 8691:dimension 8652:curvature 8588:− 8460:geodesics 8317:isotropic 8196:embedding 8129:ellipsoid 8055:astronomy 8051:mechanics 7884:open ball 7880:open sets 7774:rotations 7735:→ 7727:→ 7676:∘ 7640:∘ 7632:− 7575:form the 7546:→ 7538:→ 7478:− 7451:→ 7429:→ 7375:→ 7325:→ 7267:→ 7103:⋯ 7066:↦ 7043:… 7020:→ 6946:→ 6933:⋅ 6917:… 6909:→ 6896:⋅ 6876:↦ 6850:→ 6799:… 6741:↦ 6691:→ 6678:↦ 6641:→ 6575:→ 6553:→ 6497:→ 6491:: 6466:→ 6458:→ 6453:→ 6445:: 6440:→ 6382:→ 6374:→ 6369:→ 6361:: 6356:→ 6328:→ 6322:: 6276:‖ 6269:‖ 6266:− 6257:‖ 6250:‖ 6247:− 6238:‖ 6225:‖ 6199:⋅ 6166:⋅ 6145:⋅ 6106:‖ 6100:‖ 6094:‖ 6079:‖ 5986:bijection 5966:manifolds 5944:spherical 5872:) from a 5759:→ 5706:⋅ 5677:α 5636:α 5613:α 5590:α 5554:α 5541:α 5528:α 5371:… 5332:→ 5298:→ 5253:… 5194:→ 5140:… 5088:… 5021:… 4956:⋅ 4920:‖ 4907:‖ 4867:… 4691:→ 4645:→ 4578:otherwise 4558:⁡ 4552:− 4549:π 4537:μ 4529:λ 4504:⁡ 4481:μ 4472:λ 4466:⁡ 4317:arccosine 4254:⋅ 4241:⁡ 4232:θ 4208:→ 4124:→ 4111:⋅ 4106:→ 4006:→ 3993:⋅ 3988:→ 3970:→ 3957:⋅ 3952:→ 3927:→ 3914:⋅ 3909:→ 3893:− 3888:→ 3875:⋅ 3870:→ 3852:→ 3839:⋅ 3834:→ 3802:→ 3784:→ 3764:⋅ 3752:→ 3734:→ 3688:→ 3675:⋅ 3670:→ 3470:→ 3424:→ 3351:→ 3315:⋅ 3276:→ 3156:≤ 3009:→ 2924:→ 2869:⋅ 2858:‖ 2852:‖ 2809:⟩ 2797:⟨ 2785:of their 2741:⟩ 2729:⟨ 2721:(that is 2699:⟩ 2687:⟨ 2684:↦ 2653:→ 2644:→ 2636:× 2631:→ 2587:→ 2533:→ 2391:≤ 2388:λ 2385:≤ 2370:→ 2357:λ 2246:∈ 2243:λ 2230:λ 2218:λ 2215:− 2138:∈ 2135:λ 2123:→ 2110:λ 2102:→ 2086:λ 2083:− 1985:∈ 1982:λ 1970:→ 1957:λ 1902:→ 1875:→ 1845:→ 1818:→ 1782:→ 1774:∈ 1740:→ 1702:→ 1671:→ 1624:→ 1616:∈ 1557:direction 1541:→ 1514:→ 1480:→ 1421:∈ 1409:∈ 1394:→ 1369:→ 1313:→ 1286:Subspaces 1167:→ 1044:→ 829:→ 803:dimension 799:dimension 780:→ 752:over the 737:over the 406:congruent 354:polytopes 325:In 1637, 298:Euclid's 74:dimension 51:Euclid's 9616:Category 9592:See also 9392:Manifold 9269:(1987), 8688:infinite 8662:See also 8634:To take 8533:Einstein 8415:that is 8405:manifold 8395:Manifold 8313:coplanar 8133:a priori 8121:embedded 8113:manifold 8043:sciences 7978:. Later 7914:complete 7817:Topology 7770:identity 7527:The map 6541:′ 5978:isometry 4800:[0, 4776:[0, 4773:interval 4742:, where 4525:if  4362:oriented 3224:triangle 3016:‖ 2994:‖ 2955:distance 2717:that is 2453:parallel 472:The set 421:physical 394:rotation 300:Elements 134:theorems 124:Elements 110:Ancient 53:Elements 43:geometry 9514:Simplex 9452:Fractal 9234:1009557 8704:physics 8642:uses a 8636:gravity 8172:Discuss 8099:Beside 8063:geodesy 8047:physics 7922:bounded 7753:or the 6827:⁠ 6769:⁠ 4820:/2] 4804:/2] 4780:/2] 4315:of the 4311:is the 3401:form a 3055:segment 2290:segment 1150:and an 863:is the 517:and an 402:subsets 398:figures 386:motions 335:algebra 239:as the 129:proving 122:in his 105:physics 85:-spaces 9471:shapes 9277:  9255:  9232:  9222:  9194:  8650:. The 8467:sphere 8435:, and 8419:to an 8239:and a 8237:circle 8222:metric 8192:axioms 8137:graphs 8053:, and 8039:shapes 8022:length 8016:is an 7964:axioms 7934:Euclid 7655:fixes 6427:, and 6186:since 5938:. The 5217:origin 5060:, the 4812:[− 4794:. The 4611:, and 4428:< 0 4409:< 2 4388:modulo 4360:In an 4309:arccos 4307:where 4238:arccos 4088:Here, 3294:) are 3123:metric 3051:length 2893:metric 2605:is an 2181:where 2028:where 1148:origin 1130:as an 869:action 814:points 748:is an 515:origin 453:— the 441:number 316:axioms 245:-space 120:Euclid 101:spaces 9575:Eight 9570:Seven 9550:Three 9427:Krull 9188:Wiley 8505:. A 8332:field 8323:in a 8226:field 8162:split 8077:, or 8029:Usage 7990:(see 7714:index 7659:. So 7560:is a 5984:is a 5874:dense 5864:be a 4996:basis 4842:basis 4792:] 4784:[ 4555:angle 4501:angle 4463:angle 4420:< 4405:< 4348:≤ 180 4182:angle 4168:Angle 4162:Angle 3053:of a 1719:then 1685:is a 1574:then 1463:is a 962:Note: 754:reals 414:below 412:(see 314:, or 306:prove 241:real 9560:Five 9555:Four 9535:Zero 9469:and 9275:ISBN 9253:ISBN 9220:ISBN 9192:ISBN 9018:and 8912:and 8397:and 8241:line 7994:and 7982:and 7916:and 7893:The 7878:The 7809:and 7704:The 7694:and 7586:Let 7242:ISO( 7206:and 6400:and 5946:and 5915:The 5285:and 5175:, a 5116:and 5052:the 4984:for 4816:/2, 4788:/2, 4746:and 4736:and 4673:and 4621:and 4449:and 4441:and 4382:and 4374:and 4344:0 ≤ 4342:(or 4333:0 ≤ 4191:and 3507:and 3452:and 3395:are 3383:and 3259:and 3249:and 3081:and 3049:The 2953:The 2895:and 2834:The 2447:and 2302:0 ≤ 2296:and 2282:The 2050:and 2032:and 1932:line 1658:and 1332:flat 1296:Let 797:The 713:and 622:the 529:and 451:acts 165:and 95:and 9565:Six 9545:Two 9540:One 9212:doi 8959:As 8535:'s 8531:of 8520:). 8493:An 8170:. ( 8107:of 8092:of 8001:In 7998:). 7761:or 7602:to 7406:if 7240:of 7220:or 7188:the 7186:as 6624:If 5976:An 5923:of 5879:of 5843:+ 1 5830:An 5737:of 5575:if 5319:of 5064:of 4895:of 4761:or 4603:If 4424:− 2 4222:is 4195:in 3501:If 3399:or 3298:or 3263:of 2842:is 2760:). 2758:≠ 0 2312:or 2306:≤ 1 2054:is 1859:.) 1689:of 1566:If 1559:of 1350:of 1342:of 1338:or 1185:to 1154:of 1026:or 849:or 763:If 634:the 501:of 416:). 206:or 150:). 60:of 9632:: 9314:, 9308:, 9230:MR 9228:, 9218:, 9190:, 9128:^ 9113:^ 9062:^ 8627:, 8623:, 8431:, 8427:, 8403:A 8338:. 8293:. 8255:. 8194:, 8174:) 8139:. 8096:. 8081:. 8073:, 8069:, 8065:, 8061:, 8049:, 8007:, 7940:. 7890:. 7875:. 7813:. 7780:. 7765:. 7523:O. 7352:– 7248:. 7234:E( 7216:, 7194:. 6660:∈ 6422:∈ 6414:, 6409:∈ 6308:. 5968:. 4989:≠ 4822:. 4766:− 4739:AC 4733:AB 4624:AC 4618:AB 4607:, 4430:. 4357:. 4337:≤ 3510:AC 3504:AB 3386:AC 3380:AB 3374:. 3237:. 3230:. 3219:PQ 3118:. 3071:, 3059:PQ 2826:⋅ 2772:⋅ 2558:. 2314:QP 2310:PQ 2304:𝜆 2279:. 1563:. 1334:, 1330:A 1260:. 1021:− 1007:= 1003:+ 985:, 887:+ 744:A 741:. 725:A 640:. 322:. 279:. 9581:n 9345:e 9338:t 9331:v 9261:. 9214:: 9174:. 9108:. 9096:. 9072:. 9035:, 9032:y 9026:x 9006:, 9001:2 8993:y 8987:, 8982:2 8974:x 8961:f 8947:. 8944:) 8941:y 8938:( 8935:f 8929:) 8926:x 8923:( 8920:f 8900:, 8895:2 8887:) 8884:y 8881:( 8878:f 8856:, 8851:2 8843:) 8840:x 8837:( 8834:f 8811:0 8808:= 8805:) 8802:y 8799:( 8796:f 8787:) 8784:x 8781:( 8778:f 8769:) 8766:y 8760:+ 8757:x 8751:( 8748:f 8629:z 8625:y 8621:x 8617:t 8601:, 8596:2 8592:t 8583:2 8579:z 8575:+ 8570:2 8566:y 8562:+ 8557:2 8553:x 7859:, 7854:n 7849:R 7796:r 7792:r 7732:f 7724:f 7682:, 7679:g 7673:t 7670:= 7667:f 7657:P 7643:f 7635:1 7628:t 7624:= 7621:g 7611:) 7609:P 7607:( 7605:f 7600:P 7596:t 7592:f 7588:P 7581:P 7573:P 7543:f 7535:f 7501:( 7493:. 7490:) 7487:O 7484:( 7481:f 7475:) 7472:P 7469:( 7466:f 7463:= 7458:) 7447:P 7444:O 7436:( 7426:f 7412:E 7408:O 7388:( 7380:, 7371:Q 7368:P 7354:P 7350:Q 7322:f 7310:E 7306:f 7279:. 7276:v 7273:+ 7270:P 7264:P 7246:) 7244:n 7238:) 7236:n 7192:n 7172:n 7167:R 7134:. 7130:) 7124:n 7120:e 7114:n 7110:x 7106:+ 7100:+ 7095:1 7091:e 7085:1 7081:x 7077:+ 7074:O 7070:( 7059:) 7054:n 7050:x 7046:, 7038:1 7034:x 7030:( 7023:E 7011:n 7006:R 6966:( 6958:, 6953:) 6942:P 6939:O 6928:n 6924:e 6920:, 6914:, 6905:P 6902:O 6891:1 6887:e 6881:( 6869:P 6860:n 6855:R 6843:E 6815:) 6810:n 6806:e 6802:, 6796:, 6791:1 6787:e 6783:, 6780:O 6777:( 6753:. 6750:v 6747:+ 6744:O 6738:v 6726:O 6704:( 6696:, 6687:P 6684:O 6675:P 6662:E 6658:O 6638:E 6626:E 6592:( 6582:) 6571:P 6568:O 6560:( 6550:f 6545:+ 6538:O 6534:= 6531:) 6528:P 6525:( 6522:f 6500:F 6494:E 6488:f 6463:F 6450:E 6437:f 6424:F 6420:′ 6417:O 6411:E 6407:O 6402:F 6398:E 6379:F 6366:E 6353:f 6331:F 6325:E 6319:f 6290:. 6286:) 6280:2 6272:y 6261:2 6253:x 6242:2 6234:y 6231:+ 6228:x 6221:( 6214:2 6211:1 6205:= 6202:y 6196:x 6172:, 6169:y 6163:x 6160:= 6157:) 6154:y 6151:( 6148:f 6142:) 6139:x 6136:( 6133:f 6109:, 6103:x 6097:= 6091:) 6088:x 6085:( 6082:f 6055:. 6052:) 6049:y 6046:, 6043:x 6040:( 6037:d 6034:= 6031:) 6028:) 6025:y 6022:( 6019:f 6016:, 6013:) 6010:x 6007:( 6004:f 6001:( 5998:d 5955:f 5936:) 5934:x 5932:( 5930:f 5925:E 5921:x 5903:. 5898:n 5893:R 5881:E 5862:f 5858:n 5854:E 5841:n 5836:n 5772:( 5764:. 5755:P 5752:O 5739:E 5735:P 5719:. 5714:i 5710:e 5703:v 5681:i 5666:i 5650:3 5646:e 5640:3 5632:+ 5627:2 5623:e 5617:2 5609:+ 5604:1 5600:e 5594:1 5586:= 5583:v 5563:) 5558:3 5550:, 5545:2 5537:, 5532:1 5524:( 5504:) 5501:z 5498:, 5495:y 5492:, 5489:x 5486:( 5466:) 5461:3 5457:e 5453:, 5448:2 5444:e 5440:, 5435:1 5431:e 5427:( 5407:v 5387:. 5382:n 5378:e 5374:, 5368:, 5363:1 5359:e 5348:v 5329:E 5317:v 5295:E 5283:E 5269:) 5264:n 5260:e 5256:, 5250:, 5245:1 5241:e 5237:, 5234:O 5231:( 5221:O 5213:E 5199:, 5191:E 5173:E 5156:) 5151:i 5147:b 5143:, 5137:, 5132:1 5128:b 5124:( 5104:) 5099:i 5095:e 5091:, 5085:, 5080:1 5076:e 5072:( 5058:i 5040:, 5037:) 5032:n 5028:b 5024:, 5018:, 5013:1 5009:b 5005:( 4991:j 4987:i 4972:0 4969:= 4964:j 4960:e 4951:i 4947:e 4926:1 4923:= 4915:i 4911:e 4899:( 4883:) 4878:n 4874:e 4870:, 4864:, 4859:1 4855:e 4851:( 4818:π 4814:π 4802:π 4790:π 4786:π 4778:π 4768:θ 4764:π 4759:θ 4755:θ 4748:C 4744:B 4728:A 4704:( 4696:. 4687:C 4684:A 4655:( 4641:B 4638:A 4613:C 4609:B 4605:A 4582:. 4573:) 4570:y 4567:, 4564:x 4561:( 4519:) 4516:y 4513:, 4510:x 4507:( 4495:{ 4490:= 4487:) 4484:y 4478:, 4475:x 4469:( 4451:μ 4447:λ 4443:y 4439:x 4426:π 4422:θ 4418:π 4416:− 4411:π 4407:θ 4403:π 4394:π 4392:2 4384:x 4380:y 4376:y 4372:x 4355:π 4346:θ 4339:π 4335:θ 4329:θ 4292:) 4285:| 4281:y 4277:| 4271:| 4267:x 4263:| 4257:y 4251:x 4245:( 4235:= 4205:E 4193:y 4189:x 4185:θ 4140:( 4132:0 4129:= 4120:C 4117:A 4102:B 4099:A 4070:. 4065:2 4060:| 4055:C 4052:A 4048:| 4044:+ 4039:2 4034:| 4029:B 4026:A 4022:| 4018:= 4002:C 3999:A 3984:C 3981:A 3975:+ 3966:B 3963:A 3948:B 3945:A 3939:= 3923:C 3920:A 3905:B 3902:A 3896:2 3884:C 3881:A 3866:C 3863:A 3857:+ 3848:A 3845:B 3830:A 3827:B 3821:= 3809:) 3798:C 3795:A 3789:+ 3780:A 3777:B 3769:( 3759:) 3748:C 3745:A 3739:+ 3730:A 3727:B 3719:( 3714:= 3698:( 3684:C 3681:B 3666:C 3663:B 3657:= 3648:2 3643:| 3638:C 3635:B 3631:| 3598:. 3593:2 3588:| 3583:C 3580:A 3576:| 3572:+ 3567:2 3562:| 3557:B 3554:A 3550:| 3546:= 3541:2 3536:| 3531:C 3528:B 3524:| 3480:) 3466:C 3463:A 3434:) 3420:B 3417:A 3392:A 3348:E 3324:0 3321:= 3318:v 3312:u 3292:E 3273:E 3261:v 3257:u 3214:R 3198:. 3195:) 3192:Q 3189:, 3186:R 3183:( 3180:d 3177:+ 3174:) 3171:R 3168:, 3165:P 3162:( 3159:d 3153:) 3150:Q 3147:, 3144:P 3141:( 3138:d 3105:| 3101:Q 3098:P 3094:| 3083:Q 3079:P 3075:) 3073:Q 3069:P 3067:( 3065:d 3029:( 3021:. 3005:Q 3002:P 2989:= 2986:) 2983:Q 2980:, 2977:P 2974:( 2971:d 2921:E 2908:E 2877:. 2872:x 2866:x 2861:= 2855:x 2840:x 2828:y 2824:x 2806:y 2803:, 2800:x 2774:y 2770:x 2756:x 2738:x 2735:, 2732:x 2696:y 2693:, 2690:x 2677:) 2674:y 2671:, 2668:x 2665:( 2657:R 2641:E 2628:E 2603:E 2584:E 2552:S 2538:. 2530:S 2525:+ 2522:P 2512:S 2508:P 2504:S 2500:P 2484:. 2481:v 2478:+ 2475:S 2472:= 2469:T 2457:v 2449:T 2445:S 2412:( 2404:. 2399:} 2394:1 2382:0 2377:| 2366:Q 2363:P 2354:+ 2351:P 2346:{ 2341:= 2338:P 2335:Q 2332:= 2329:Q 2326:P 2298:Q 2294:P 2261:. 2256:} 2250:R 2238:| 2233:Q 2227:+ 2224:P 2221:) 2212:1 2209:( 2204:{ 2190:O 2183:O 2161:( 2153:, 2148:} 2142:R 2130:| 2119:Q 2116:O 2107:+ 2098:P 2095:O 2089:) 2080:1 2077:( 2074:+ 2071:O 2066:{ 2052:Q 2048:P 2034:Q 2030:P 2008:( 2000:, 1995:} 1989:R 1977:| 1966:Q 1963:P 1954:+ 1951:P 1946:{ 1899:E 1872:E 1842:V 1815:V 1789:} 1779:V 1771:v 1766:| 1761:v 1758:+ 1755:P 1750:{ 1745:= 1737:V 1732:+ 1729:P 1707:, 1699:E 1668:V 1656:E 1652:P 1636:. 1631:} 1621:F 1613:v 1608:| 1603:v 1600:+ 1597:P 1592:{ 1587:= 1584:F 1572:F 1568:P 1561:F 1538:F 1511:F 1499:F 1485:. 1477:E 1461:F 1439:( 1429:} 1424:F 1418:Q 1415:, 1412:F 1406:P 1401:| 1390:Q 1387:P 1379:{ 1374:= 1366:F 1352:E 1348:F 1344:E 1310:E 1298:E 1258:n 1238:n 1233:R 1221:n 1205:. 1200:n 1195:R 1183:E 1164:E 1144:n 1140:E 1112:n 1107:R 1063:. 1054:) 1040:Q 1037:P 1023:P 1019:Q 1014:v 1009:Q 1005:v 1001:P 996:v 989:) 987:Q 983:P 981:( 974:+ 970:+ 966:+ 947:. 944:w 941:+ 938:) 935:v 932:+ 929:P 926:( 923:= 920:) 917:w 914:+ 911:v 908:( 905:+ 902:P 889:v 885:P 880:P 876:v 826:E 810:E 785:. 777:E 765:E 695:n 690:R 666:n 661:E 638:n 630:n 608:n 603:R 581:. 576:n 571:R 544:n 539:R 527:n 511:n 503:n 487:n 482:R 350:n 261:n 256:R 243:n 221:n 216:E 192:n 187:E 89:n 83:n 77:n 20:)

Index

Euclidean spaces

geometry
physical space
Euclid's Elements
three-dimensional space
Euclidean geometry
mathematics
dimension
Euclidean lines
Euclidean planes
spaces
physics
Greek geometers
ancient Greek
Euclid
proving
theorems
postulates
straight line
parallel postulate
non-Euclidean geometries
axiomatic theory
vector spaces
linear algebra
isomorphic
Cartesian coordinates
real n-space
dot product
ancient Greeks

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.