Knowledge

Regular polytope

Source 📝

3147: 25: 3008:. To obtain a fold-out net of a polyhedron, one takes the surface of the polyhedron and cuts it along just enough edges so that the surface may be laid out flat. This gives a plan for the net of the unfolded polyhedron. Since the Platonic solids have only triangles, squares and pentagons for faces, and these are all constructible with a ruler and compass, there exist ruler-and-compass methods for drawing these fold-out nets. The same applies to star polyhedra, although here we must be careful to make the net for only the visible outer surface. 142: 2325: 2318: 1283: 193: 1055: 850: 1008: 2991: 89: 836: 2332: 2339: 171: 1015: 1001: 116: 802: 795: 788: 781: 3082:
even imagine building a model of this fold-out net, as one draws a polyhedron's fold-out net on a piece of paper. Sadly, we could never do the necessary folding of the 3-dimensional structure to obtain the 4-dimensional polytope because of the constraints of the physical universe. Another way to "draw" the higher-dimensional shapes in 3 dimensions is via some kind of projection, for example, the analogue of either
2209: 2216: 2188: 1243: 1236: 1229: 843: 3036: 2202: 2195: 1276: 1048: 3050: 2731: 1269: 1041: 2794:. Certain restrictions are imposed on the set that are similar to properties satisfied by the classical regular polytopes (including the Platonic solids). The restrictions, however, are loose enough that regular tessellations, hemicubes, and even objects as strange as the 11-cell or stranger, are all examples of regular polytopes. 3094:) has some examples of such orthographic projections. Note that immersing even 4-dimensional polychora directly into two dimensions is quite confusing. Easier to understand are 3-d models of the projections. Such models are occasionally found in science museums or mathematics departments of universities (such as that of the 2801:
of the abstract polytope, such that there is a one-to-one mapping from the abstract elements to the corresponding faces of the geometric realisation. Thus, any geometric polytope may be described by the appropriate abstract poset, though not all abstract polytopes have proper geometric realizations.
2663:
In the first part of the 20th century, Coxeter and Petrie discovered three infinite structures {4, 6}, {6, 4} and {6, 6}. They called them regular skew polyhedra, because they seemed to satisfy the definition of a regular polyhedron — all the vertices, edges and faces are alike, all the angles
2537:
contains 8 cubical cells. It consists of two cubes in parallel hyperplanes with corresponding vertices cross-connected in such a way that the 8 cross-edges are equal in length and orthogonal to the 12+12 edges situated on each cube. The corresponding faces of the two cubes are connected to form the
2761:
This concept may be easier for the reader to grasp if one considers the relationship of the cube and the hemicube. An ordinary cube has 8 corners, they could be labeled A to H, with A opposite H, B opposite G, and so on. In a hemicube, A and H would be treated as the same corner. So would B and G,
3081:
The second approach is to embed the higher-dimensional objects in three-dimensional space, using methods analogous to the ways in which three-dimensional objects are drawn on the plane. For example, the fold out nets mentioned in the previous section have higher-dimensional equivalents. One might
3011:
If this net is drawn on cardboard, or similar foldable material (for example, sheet metal), the net may be cut out, folded along the uncut edges, joined along the appropriate cut edges, and so forming the polyhedron for which the net was designed. For a given polyhedron there may be many fold-out
2986:
gave what amount to ruler-and-compass constructions for the five Platonic solids. However, the merely practical question of how one might draw a straight line in space, even with a ruler, might lead one to question what exactly it means to "construct" a regular polyhedron. (One could ask the same
2687:
would be a zig-zag. It seems to satisfy the definition of a regular polygon — all the edges are the same length, all the angles are the same, and the figure has no loose ends (because they can never be reached). More importantly, perhaps, there are symmetries of the zig-zag that can map any
3122:
technology. To understand how this might work, imagine what one would see if space were filled with cubes. The viewer would be inside one of the cubes, and would be able to see cubes in front of, behind, above, below, to the left and right of himself. If one could travel in these directions, one
2827:
Any classical regular polytope has an abstract equivalent which is regular, obtained by taking the set of faces. But non-regular classical polytopes can have regular abstract equivalents, since abstract polytopes do not retain information about angles and edge lengths, for example. And a regular
2379: 3077:
The first approach, suitable for four dimensions, uses four-dimensional stereography. Depth in a third dimension is represented with horizontal relative displacement, depth in a fourth dimension with vertical relative displacement between the left and right images of the stereograph.
3073:
In higher dimensions, it becomes harder to say what one means by "constructing" the objects. Clearly, in a 3-dimensional universe, it is impossible to build a physical model of an object having 4 or more dimensions. There are several approaches normally taken to overcome this matter.
3106:
into a kind of four dimensional object, where the fourth dimension is taken to be time. In this way, we can see (if not fully grasp) the full four-dimensional structure of the four-dimensional regular polytopes, via such cutaway cross sections. This is analogous to the way a
2599:
This is a "recursive" definition. It defines regularity of higher dimensional figures in terms of regular figures of a lower dimension. There is an equivalent (non-recursive) definition, which states that a polytope is regular if it has a sufficient degree of symmetry.
3157:
Locally, this space seems like the one we are familiar with, and therefore, a virtual-reality system could, in principle, be programmed to allow exploration of these "tessellations", that is, of the 4-dimensional regular polytopes. The mathematics department at
2959:. Constructing some regular polygons in this way is very simple (the easiest is perhaps the equilateral triangle), some are more complex, and some are impossible ("not constructible"). The simplest few regular polygons that are impossible to construct are the 2550:
by joining the 8 vertices of each of its cubical faces to an additional vertex to form the four-dimensional analogue of a pyramid. Both figures, as well as other 4-dimensional figures, can be directly visualised and depicted using 4-dimensional stereographs.
2258:
Our understanding remained static for many centuries after Euclid. The subsequent history of the regular polytopes can be characterised by a gradual broadening of the basic concept, allowing more and more objects to be considered among their number.
3177:
is known. This is because of an important theorem in the study of abstract regular polytopes, providing a technique that allows the abstract regular polytope to be constructed from its symmetry group in a standard and straightforward manner.
3101:
The intersection of a four (or higher) dimensional regular polytope with a three-dimensional hyperplane will be a polytope (not necessarily regular). If the hyperplane is moved through the shape, the three-dimensional slices can be combined,
2035:
they do not contain. The remaining thing to check is that any two hyperplanes with adjacent numbers cannot be orthogonal, whereas hyperplanes with non-adjacent numbers are orthogonal. This can be done using induction (since all facets of
651:
of a regular polytope is also a regular polytope. The Schläfli symbol for the dual polytope is just the original symbol written backwards: {3, 3} is self-dual, {3, 4} is dual to {4, 3}, {4, 3, 3} to {3, 3, 4} and so on.
2973:
in this sense refers only to ideal constructions with ideal tools. Of course reasonably accurate approximations can be constructed by a range of methods; while theoretically possible constructions may be impractical.
3019:
provides sets of plastic triangles, squares, pentagons and hexagons that can be joined edge-to-edge in a large number of different ways. A child playing with such a toy could re-discover the Platonic solids (or the
2783:
By 1994 GrĂźnbaum was considering polytopes abstractly as combinatorial sets of points or vertices, and was unconcerned whether faces were planar. As he and others refined these ideas, such sets came to be called
2664:
are the same, and the figure has no free edges. Nowadays, they are called infinite polyhedra or apeirohedra. The regular tilings of the plane {4, 4}, {3, 6} and {6, 3} can also be regarded as infinite polyhedra.
3456: 2616:
So for example, the cube is regular because if we choose a vertex of the cube, and one of the three edges it is on, and one of the two faces containing the edge, then this triplet, known as a
2382:
A 3D projection of a rotating tesseract. This tesseract is initially oriented so that all edges are parallel to one of the four coordinate space axes. The rotation takes place in the xw plane.
474:
The idea of a polytope is sometimes generalised to include related kinds of geometrical object. Some of these have regular examples, as discussed in the section on historical discovery below.
3062: 3027:
In theory, almost any material may be used to construct regular polyhedra. They may be carved out of wood, modeled out of wire, formed from stained glass. The imagination is the limit.
2750:
object whose facets are not icosahedra, but are "hemi-icosahedra" — that is, they are the shape one gets if one considers opposite faces of the icosahedra to be actually the
3004:
The English word "construct" has the connotation of systematically building the thing constructed. The most common way presented to construct a regular polyhedron is via a
2762:
and so on. The edge AB would become the same edge as GH, and the face ABEF would become the same face as CDGH. The new shape has only three faces, 6 edges and 4 corners.
3639:
Schläfli, L. (1858). "On the multiple integral ∫^ n dxdy... dz, whose limits are p_1= a_1x+ b_1y+…+ h_1z> 0, p_2> 0,..., p_n> 0, and x^ 2+ y^ 2+…+ z^ 2< 1".
1609: 3118:
Another way a three-dimensional viewer can comprehend the structure of a four-dimensional polytope is through being "immersed" in the object, perhaps via some form of
1561: 2033: 1953: 1827: 1807: 1440:, but not every finite Coxeter groups may be realised as the isometry group of a regular polytope. Regular polytopes are in bijection with Coxeter groups with linear 2406:, pp. 143–144) for more details. Schläfli called such a figure a "polyschem" (in English, "polyscheme" or "polyschema"). The term "polytope" was introduced by 2710:
has its x, y, z, etc. coordinates as complex numbers. This effectively doubles the number of dimensions. A polytope constructed in such a unitary space is called a
1715: 1677: 1639: 1514: 1480: 2120: 1853: 258:
of the polytope) — cells, faces and so on — are also transitive on the symmetries of the polytope, and are themselves regular polytopes of dimension
2094: 2074: 2054: 2013: 1993: 1973: 1933: 1913: 1893: 1873: 1787: 1763: 1743: 659:
of a regular polytope is the dual of the dual polytope's facet. For example, the vertex figure of {3, 3, 4} is {3, 4}, the dual of which is {4, 3} — a
2566:. From the mathematical point of view, however, these objects have the same aesthetic qualities as their more familiar two and three-dimensional relatives. 1725:
The bijection between regular polytopes and Coxeter groups with linear Coxeter-Dynkin diagram can be understood as follows. Consider a regular polytope
3015:
Numerous children's toys, generally aimed at the teen or pre-teen age bracket, allow experimentation with regular polygons and polyhedra. For example,
2790:. An abstract polytope is defined as a partially ordered set (poset), whose elements are the polytope's faces (vertices, edges, faces etc.) ordered by 2622:, (vertex, edge, face) can be mapped to any other such flag by a suitable symmetry of the cube. Thus we can define a regular polytope very succinctly: 2834:
are regular in the abstract world, for example, whereas only those having equal angles and edges of equal length are regular in the classical world.
2706:
has a real part, which is the bit we are all familiar with, and an imaginary part, which is a multiple of the square root of minus one. A complex
429:
and above, the simplex, hypercube and orthoplex are the only regular polytopes. There are no exceptional regular polytopes in these dimensions.
3626:
Schläfli, L. (1855). "RÊduction d'une intÊgrale multiple, qui comprend l'arc de cercle et l'aire du triangle sphÊrique comme cas particuliers".
2487:
In five and more dimensions, there are exactly three regular polytopes, which correspond to the tetrahedron, cube and octahedron: these are the
2263:(Bradwardinus) was the first to record a serious study of star polygons. Various star polyhedra appear in Renaissance art, but it was not until 3115:
of some sort, however, even a simple animation such as the one shown can already give some limited insight into the structure of the polytope.
2688:
pair of a vertex and attached edge to any other. Since then, other regular apeirogons and higher apeirotopes have continued to be discovered.
2608:-polytope is regular if any set consisting of a vertex, an edge containing it, a 2-dimensional face containing the edge, and so on up to 492:
in the 19th century, and a slightly modified form has become standard. The notation is best explained by adding one dimension at a time.
2765:
The 11-cell cannot be formed with regular geometry in flat (Euclidean) hyperspace, but only in positively curved (elliptic) hyperspace.
3323: 3159: 3111:
reassembles two-dimensional images to form a 3-dimensional representation of the organs being scanned. The ideal would be an animated
3016: 2420:
is probably the most comprehensive printed treatment of Schläfli's and similar results to date. Schläfli showed that there are six
4329: 2939:
be regular itself – for example, the square pyramid, all of whose facets and vertex figures are regular abstract polygons.
2824:
The definition of regularity in terms of the transitivity of flags as given in the introduction applies to abstract polytopes.
2402:. Between 1880 and 1900, Schläfli's results were rediscovered independently by at least nine other mathematicians — see 3721: 3554: 3533: 3261: 3173:
Normally, for abstract regular polytopes, a mathematician considers that the object is "constructed" if the structure of its
3289: 460: 3764: 3577:. Problèmes Combinatoires et ThĂŠorie des Graphes, Colloquium Internationale CNRS, Orsay. Vol. 260. pp. 191–197. 3377: 3338: 749: 3701: 3586:. Mathematical and physical sciences, NATO Advanced Study Institute. Vol. 440. Kluwer Academic. pp. 43–70. 3489: 2390:, examined and characterised the regular polytopes in higher dimensions. His efforts were first published in full in 681:, i.e. reads the same forwards and backwards, then the polyhedron is self-dual. The self-dual regular polytopes are: 68: 46: 39: 2758:). The hemi-icosahedron has only 10 triangular faces, and 6 vertices, unlike the icosahedron, which has 20 and 12. 2595:− 1)-dimensional faces are all regular and congruent, and whose vertex figures are all regular and congruent. 2530: 3095: 1444:(without branch point) and an increasing numbering of the nodes. Reversing the numbering gives the dual polytope. 3220: 737: 2738:
is derived from a cube by equating opposite vertices, edges, and faces. It has 4 vertices, 6 edges, and 3 faces.
3678: 3591: 3512: 3371: 3150: 741: 2671:
issued a call to the geometric community to consider more abstract types of regular polytopes that he called
2353: 2346: 2272: 2268: 761: 4346: 3306: 2148: 757: 753: 2476:, can be seen as a transitional form between the hypercube and 16-cell, analogous to the way that the 2414:
some twenty years later. The term "polyhedroids" was also used in earlier literature (Hilbert, 1952).
3210: 2935:
Unlike the case for Euclidean polytopes, an abstract polytope with regular facets and vertex figures
2500: 2421: 2308: 2292: 463:
to one another. Indeed, symmetry groups are sometimes named after regular polytopes, for example the
433: 2122:
such that adjacent numbers are linked by at least one edge and non-adjacent numbers are not linked.
3787: 3479: 3305:
Some interesting fold-out nets of the cube, octahedron, dodecahedron and icosahedron are available
2956: 2955:
The traditional way to construct a regular polygon, or indeed any other figure on the plane, is by
1524:(both can be distinguished by the increasing numbering of the nodes of the Coxeter-Dynkin diagram), 715: 33: 3757: 3170:
with dodecahedra. Such a tessellation forms an example of an infinite abstract regular polytope.
3087: 3083: 2658: 2135:
The earliest surviving mathematical treatment of regular polygons and polyhedra comes to us from
1766: 407: 228: 395:≥ 3. The triangle is the 2-simplex. The square is both the 2-hypercube and the 2-orthoplex. The 3146: 2576:
A regular polyhedron is a polyhedron whose faces are all congruent regular polygons, and whose
2299: 1570: 1441: 426: 411: 50: 3705: 3249: 1530: 4301: 4294: 4287: 3123:
could explore the array of cubes, and gain an understanding of its geometrical structure. An
2970: 2056:
are again regular polytopes). Therefore, the Coxeter-Dynkin diagram of the isometry group of
2018: 1938: 1812: 1792: 745: 369: 3826: 3804: 3792: 3582:
GrĂźnbaum, B. (1993). "Polyhedra with hollow faces". In Bisztriczky, T.; et al. (eds.).
3127:
is not a polytope in the traditional sense. In fact, it is a tessellation of 3-dimensional (
3958: 3905: 2776:
independently discovered the same shape. He had earlier discovered a similar polytope, the
2735: 2481: 2157: 1693: 1655: 1617: 1492: 1458: 944: 901: 814: 726: 468: 464: 8: 4313: 4212: 3962: 2634: 2518:
had developed the theory of regular polytopes in four and higher dimensions, such as the
2099: 1832: 2573:
A regular polygon is a polygon whose edges are all equal and whose angles are all equal.
4182: 4132: 4082: 4039: 4009: 3969: 3932: 3750: 3606: 3501: 3199: 2612:−1 dimensions, can be mapped to any other such set by a symmetry of the polytope. 2569:
At the start of the 20th century, the definition of a regular polytope was as follows.
2504: 2411: 2360: 2280: 2260: 2079: 2059: 2039: 1998: 1978: 1958: 1918: 1898: 1878: 1858: 1772: 1748: 1728: 551: 2668: 2515: 2387: 511:}. So an equilateral triangle is {3}, a square {4}, and so on indefinitely. A regular 489: 483: 318: 106: 4321: 3737: 3717: 3690: 3674: 3587: 3550: 3529: 3508: 3485: 3257: 3021: 2847: 2818: 2786: 2725: 2675:. He developed the theory of polystromata, showing examples of new objects he called 2555: 2365: 2284: 1338: 1250: 1169: 1106: 1022: 571: 415: 311: 307: 280: 276: 3012:
nets. For example, there are 11 for the cube, and over 900000 for the dodecahedron.
2533:, since they retain the familiar symmetry of their lower-dimensional analogues. The 235:, thus giving it the highest degree of symmetry. In particular, all its elements or 3890: 3879: 3868: 3857: 3848: 3839: 3778: 3467: 3167: 3140: 3131:) space. However, a 4-polytope can be considered a tessellation of a 3-dimensional 3054: 3005: 2994: 2773: 2712: 2697: 2529:
The latter are difficult (though not impossible) to visualise through a process of
2291:
proved the list complete in 1812. These polyhedra are known as collectively as the
1517: 932: 352: 299: 163: 3254:
Hypergraphics: Visualizing Complex Relationships In Arts, Science, And Technololgy
3915: 3900: 3544: 3523: 3342: 3293: 3286: 3256:. AAAS Selected Symposium. Vol. 24. Taylor & Francis. pp. 109–145. 3128: 3124: 3119: 2942:
The classical vertex figure will, however, be a realisation of the abstract one.
2747: 2618: 2288: 2264: 1564: 686: 660: 574:
are {3, 3} {3, 4} {4, 3} {3, 5} {5, 3} {3, 5/2} {5/2, 3} {5, 5/2} and {5/2, 5}. {
500: 384: 306:. These two conditions are sufficient to ensure that all faces are alike and all 272: 232: 176: 155: 129: 102: 3336: 4265: 3601: 3471: 3174: 3039: 2703: 2684: 2407: 2178: 2166: 2140: 2136: 1521: 1433: 711: 671: 497: 380: 358: 224: 202: 736:
Hyperbolic tilings and honeycombs (tilings {p,p} with p>4 in 2 dimensions,
141: 4340: 4282: 4170: 4163: 4156: 4120: 4113: 4106: 4070: 4063: 3355: 3215: 3132: 2707: 2638: 2637:
of the classical regular polytopes were generalised into what are now called
2577: 2511: 2477: 2324: 2317: 2276: 2162: 1437: 1282: 656: 648: 580: 376:
simultaneously serves as the 1-simplex, the 1-hypercube and the 1-orthoplex.
303: 1356:(i.e. upwards and downwards). Join the ends to the square to form a regular 1054: 849: 271:
Regular polytopes are the generalised analog in any number of dimensions of
4222: 3163: 2642: 2461: 2238: 1642: 1007: 938: 877: 809: 516: 452: 373: 180: 121: 2626:
A regular polytope is one whose symmetry group is transitive on its flags.
192: 4231: 4192: 4142: 4092: 4049: 4019: 3951: 3937: 2998: 2645:
of space or of the plane. For example, the symmetry group of an infinite
2469: 2445: 2429: 2410:, one of Schläfli's rediscoverers, in 1882, and first used in English by 2243: 2223: 1646: 957: 951: 913: 824: 819: 488:
A concise symbolic representation for regular polytopes was developed by
456: 340:
Regular polytopes are classified primarily according to their dimension.
212: 4217: 4201: 4151: 4101: 4058: 4028: 3942: 2676: 2646: 2453: 2233: 2155:
wrote a systematic study of mathematics, publishing it under the title
2144: 1402: 1385: 1357: 1255: 885: 678: 448: 419: 288: 151: 125: 3061: 4273: 4187: 4137: 4087: 4044: 4014: 3983: 3195:
Each of the Platonic solids occurs naturally in one form or another:
3103: 3043: 3024:), especially if given a little guidance from a knowledgeable adult. 2547: 2539: 2534: 2519: 2437: 2433: 2425: 2424:. Five of them can be seen as analogous to the Platonic solids: the 1292: 1194: 1183: 1064: 1032: 967: 667: 544: 255: 2331: 4247: 4002: 3998: 3925: 3135:
space, namely, a tessellation of the surface of a four-dimensional
3112: 3108: 2990: 2680: 2631: 2465: 2457: 2338: 1684: 1680: 835: 540: 440: 291:
quality that interests both mathematicians and non-mathematicians.
220: 147: 94: 88: 1081:, and join to form a line segment. Extend a second line of length 170: 4256: 4226: 3993: 3988: 3979: 3920: 3319: 3190: 3066: 2828:
abstract polytope may not be realisable as a classical polytope.
2777: 2769: 2743: 2563: 2559: 2543: 2523: 2473: 2449: 2394:, six years posthumously, although parts of it were published in 1718: 1483: 1447:
The classification of finite Coxeter groups, which goes back to (
1391: 1260: 859: 704: 697: 347: 310:
are alike. Note, however, that this definition does not work for
98: 3162:
has a number of pictures of what one would see if embedded in a
2630:
In the 20th century, some important developments were made. The
2378: 2165:. His work concluded with mathematical descriptions of the five 1014: 1000: 4196: 4146: 4096: 4053: 4023: 3974: 3910: 3658:
Denkschriften der Schweizerischen Naturforschenden Gesellschaft
3374:(1935), "The complete enumeration of finite groups of the form 3136: 2208: 2152: 801: 794: 787: 780: 198: 115: 2386:
It was not until the 19th century that a Swiss mathematician,
2215: 2187: 1451:), therefore implies the classification of regular polytopes: 1242: 1235: 1228: 842: 287:). The strong symmetry of the regular polytopes gives them an 3035: 2641:. Coxeter groups also include the symmetry groups of regular 2201: 2194: 1895:(the face they are the barycenter of). The isometry group of 1275: 1047: 343:
Three classes of regular polytopes exist in every dimension:
3049: 2484:
are transitional forms between the cube and the octahedron.
523:
times around its centre is denoted by the fractional value {
459:. Two distinct regular polytopes with the same symmetry are 3946: 3656:
Schläfli, L. (1901). "Theorie der vielfachen Kontinuität".
2730: 2441: 2228: 1268: 1176: 1141: 1040: 1027: 444: 284: 1769:. The fundamental domain of the isometry group action on 439:
Regular polytopes can be further classified according to
3568:. Translated by Heath, T. L. Cambridge University Press. 3354:
Other examples may be found on the web (see for example
2805:
The theory has since been further developed, largely by
2817:
Regularity has a related, though different meaning for
2510:
By the end of the 19th century, mathematicians such as
183:, an infinite polytope, represented by Schläfli symbol 3153:, {5,3,4}, of hyperbolic space projected into 3-space. 2837: 2809:, but other researchers have also made contributions. 1348:
of the same length and centered on 'O', orthogonal to
365:
Any other regular polytope is said to be exceptional.
3380: 2920:-face which contains all other faces. Note that each 2821:, since angles and lengths of edges have no meaning. 2102: 2082: 2062: 2042: 2021: 2001: 1981: 1961: 1941: 1921: 1901: 1881: 1861: 1835: 1815: 1795: 1775: 1751: 1731: 1696: 1658: 1620: 1573: 1533: 1495: 1461: 730: 154:, a four-dimensional polytope, with 120 dodecahedral 2928: â‰Ľ 0 of the original polytope becomes an ( 2866:itself. More formally, it is the abstract section 2812: 2652: 2492: 1427: 642: 128:, a three-dimensional polytope, with 12 pentagonal 3700: 3689: 3605: 3500: 3450: 2496: 2161:, which built up a logical theory of geometry and 2114: 2088: 2068: 2048: 2027: 2007: 1987: 1967: 1947: 1927: 1907: 1887: 1867: 1847: 1821: 1801: 1781: 1757: 1737: 1709: 1671: 1633: 1603: 1555: 1508: 1474: 1116:respectively from each corner, orthogonal to both 3641:Quarterly Journal of Pure and Applied Mathematics 3451:{\displaystyle r_{i}^{2}=(r_{i}r_{j})^{k_{ij}}=1} 2932: − 1)-face of the vertex figure. 2275:in 1619 that he realised these two were regular. 1649:(again the numbering allows to distinguish them), 1301:. Extend a line in opposite directions to points 988: 335: 4338: 3090:projection. Coxeter's famous book on polytopes ( 2151:(c. 417 BC – 369 BC) described all five. Later, 2130: 1216: 3687: 3600: 2858:is the set of all abstract faces which contain 2806: 2373: 1371:. Their names are, in order of dimensionality: 3584:POLYTOPES: abstract, convex, and computational 3181: 2768:A few years after GrĂźnbaum's discovery of the 2253: 1875:by the dimension of the corresponding face of 3758: 3696:. Translated by Dresden, Arnold. P Noordhoff. 2015:hyperplanes can be numbered by the vertex of 1432:Regular polytopes can be classified by their 908:in a third, orthogonal, dimension a distance 611:}. The vertex figure of the 4-polytope is a { 562:faces joining around a vertex is denoted by { 3528:(2nd ed.). Cambridge University Press. 2691: 2554:Harder still to imagine are the more modern 2499:. Descriptions of these may be found in the 1975:(since the barycenter of the whole polytope 1809:in the barycentric subdivision. The simplex 599:cells joining around an edge is denoted by { 298:dimensions may be defined as having regular 201:can be shown in this orthogonal projection ( 3575:Regularity of Graphs, Complexes and Designs 2797:A geometric polytope is understood to be a 912:from all three, and join to form a regular 451:share the same symmetry, as do the regular 317:A regular polytope can be represented by a 3765: 3751: 3671:Geometrical and Structural Crystallography 3065:An animated cut-away cross-section of the 2967:equal to 7, 9, 11, 13, 14, 18, 19, 21,... 1222:Graphs of the 2-orthoplex to 4-orthoplex. 1158:. Their names are, in order of dimension: 927:. Their names are, in order of dimension: 80: 3243: 3241: 3186:For examples of polygons in nature, see: 2987:question about the polygons, of course.) 1855:vertices which can be numbered from 0 to 1482:, the symmetric group, gives the regular 729:, {4,3,...,3,4}. These may be treated as 674:in any dimension are dual to each other. 69:Learn how and when to remove this message 3655: 3638: 3625: 3581: 3572: 3542: 3145: 3060: 3048: 3034: 2989: 2850:. The vertex figure of a given abstract 2755: 2729: 2422:regular convex polytopes in 4 dimensions 2399: 2395: 2391: 2377: 2306: 2176: 32:This article includes a list of general 16:Polytope with highest degree of symmetry 4330:List of regular polytopes and compounds 3616: 3521: 3498: 3477: 3370: 3247: 3091: 2916:is the maximal face, i.e. the notional 2417: 2403: 2125: 1448: 4339: 3250:"Visual Comprehension in n-Dimensions" 3238: 2653:Apeirotopes — infinite polytopes 2488: 1935:reflections around the hyperplanes of 774:Graphs of the 1-simplex to 4-simplex. 197:The 256 vertices and 1024 edges of an 3740:- List of abstract regular polytopes. 3668: 2719: 414:, there are several more exceptional 3738:The Atlas of Small Regular Polytopes 3030: 2507:, partially discovered by Schläfli. 768: 101:, a two-dimensional polytope with 5 18: 3716:. Courier Dover. pp. 159–192. 3652:(1860) pp54–68, 97–108. 2846:is also defined differently for an 2838:Vertex figure of abstract polytopes 2147:knew of at least three of them and 1360:. And so on for higher dimensions. 1147:. And so on for higher dimensions. 916:. And so on for higher dimensions. 718:({5/2,5,5/2}) in 4 dimensions. 587:A regular 4-polytope having cells { 477: 294:Classically, a regular polytope in 13: 2683:many faces. A simple example of a 2679:, that is, regular polytopes with 2022: 1942: 1816: 1796: 38:it lacks sufficient corresponding 14: 4358: 3731: 2538:remaining 6 cubical faces of the 2300:Regular polyhedron § History 1995:is fixed by any isometry). These 158:, represented by Schläfli symbol 132:, represented by Schläfli symbol 3710:Introduction to the Geometry of 3151:A regular dodecahedral honeycomb 2945: 2813:Regularity of abstract polytopes 2503:. Also of interest are the star 2337: 2330: 2323: 2316: 2214: 2207: 2200: 2193: 2186: 1428:Classification by Coxeter groups 1401:5. Regular triacontakaiditeron ( 1281: 1274: 1267: 1241: 1234: 1227: 1124:(i.e. upwards). Mark new points 1053: 1046: 1039: 1013: 1006: 999: 994:Graphs of the 2-cube to 4-cube. 848: 841: 834: 800: 793: 786: 779: 643:Duality of the regular polytopes 191: 169: 140: 114: 87: 23: 3688:Van der Waerden, B. L. (1954). 3364: 3335:Some of these may be viewed at 3221:Bartel Leendert van der Waerden 3619:A Short History Of Mathematics 3549:. Cambridge University Press. 3507:. Cambridge University Press. 3423: 3399: 3348: 3329: 3312: 3299: 3279: 3270: 3252:. In Brisson, David W. (ed.). 2580:are all congruent and regular. 1550: 1544: 1220: 992: 989:Measure polytopes (hypercubes) 772: 707:in 4 dimensions, {3,4,3}. 336:Classification and description 329:and regular vertex figures as 1: 3612:. Cambridge University Press. 3226: 3096:UniversitĂŠ Libre de Bruxelles 2807:McMullen & Schulte (2002) 2742:GrĂźnbaum also discovered the 2649:would be the Coxeter group . 2591:-dimensional polytope whose ( 2131:Convex polygons and polyhedra 1955:containing the vertex number 1217:Cross polytopes (orthoplexes) 279:or the regular pentagon) and 2977: 2854:-polytope at a given vertex 2374:Higher-dimensional polytopes 2336: 2329: 2322: 2315: 2273:great stellated dodecahedron 2269:small stellated dodecahedron 2213: 2206: 2199: 2192: 2185: 2096:vertices numbered from 0 to 1381:2. Square (regular tetragon) 1240: 1233: 1226: 1012: 1005: 998: 876:from it, and join to form a 799: 792: 785: 778: 622:A regular 5-polytope is an { 383:, there are infinitely many 7: 3563: 3543:Cromwell, Peter R. (1999). 3248:Brisson, David W. (2019) . 3204: 3182:Regular polytopes in nature 2950: 2254:Star polygons and polyhedra 1390:4. Regular hexadecachoron ( 10: 4363: 4319: 3746: 3706:"X. The Regular Polytopes" 3608:Abstract Regular Polytopes 3318:Instructions for building 3197: 3188: 3053:A perspective projection ( 2723: 2695: 2656: 2556:abstract regular polytopes 2297: 1337:. Join the ends to form a 1290: 1062: 888:, dimension at a distance 857: 677:If the Schläfli symbol is 481: 138: 85: 82:Regular polytope examples 3525:Regular Complex Polytopes 3503:Regular Complex Polytopes 3211:List of regular polytopes 2692:Regular complex polytopes 2501:list of regular polytopes 2139:mathematicians. The five 1604:{\displaystyle n=3,4,...} 1112:. Extend lines of length 1073:. Extend a line to point 434:list of regular polytopes 190: 3628:Journal de MathĂŠmatiques 3472:10.1112/jlms/s1-10.37.21 3231: 2957:compass and straightedge 2546:can be derived from the 2428:(or pentachoron) to the 2309:Kepler-Poinsot polyhedra 2293:Kepler-Poinsot polyhedra 1789:is given by any simplex 1556:{\displaystyle I_{2}(n)} 716:grand stellated 120-cell 3673:(2nd ed.). Wiley. 3484:(3rd ed.). Dover. 3125:infinite array of cubes 2659:Regular skew polyhedron 2028:{\displaystyle \Delta } 1948:{\displaystyle \Delta } 1822:{\displaystyle \Delta } 1802:{\displaystyle \Delta } 1767:barycentric subdivision 892:from both, and join to 325:with regular facets as 53:more precise citations. 3621:. The Riverside Press. 3604:; Schulte, S. (2002). 3452: 3154: 3070: 3058: 3046: 3001: 2780:(Coxeter 1982, 1984). 2739: 2448:(or hexadecachoron or 2383: 2116: 2090: 2070: 2050: 2029: 2009: 1989: 1969: 1949: 1929: 1909: 1889: 1869: 1849: 1823: 1803: 1783: 1759: 1739: 1711: 1673: 1635: 1605: 1557: 1510: 1476: 1442:Coxeter-Dynkin diagram 469:icosahedral symmetries 403:≥ 5 are exceptional. 3669:Smith, J. V. (1982). 3573:GrĂźnbaum, B. (1976). 3453: 3149: 3064: 3052: 3038: 2993: 2963:-sided polygons with 2746:, a four-dimensional 2733: 2583:And so on, a regular 2381: 2117: 2091: 2071: 2051: 2030: 2010: 1990: 1970: 1950: 1930: 1910: 1890: 1870: 1850: 1824: 1804: 1784: 1760: 1740: 1721:, which is self-dual. 1712: 1710:{\displaystyle F_{4}} 1674: 1672:{\displaystyle H_{4}} 1636: 1634:{\displaystyle H_{3}} 1606: 1558: 1511: 1509:{\displaystyle B_{n}} 1477: 1475:{\displaystyle A_{n}} 1186:(regular octachoron) 760:in 4 dimensions, and 507:sides is denoted by { 387:, namely the regular 323:{a, b, c, ..., y, z}, 302:(-faces) and regular 3617:Sanford, V. (1930). 3460:J. London Math. Soc. 3378: 3322:models may be found 2482:rhombic dodecahedron 2143:were known to them. 2126:History of discovery 2100: 2080: 2060: 2040: 2019: 1999: 1979: 1959: 1939: 1919: 1915:is generated by the 1899: 1879: 1859: 1833: 1813: 1793: 1773: 1749: 1729: 1694: 1656: 1618: 1571: 1531: 1493: 1459: 1197:(regular decateron) 1179:(regular hexahedron) 1097:, and likewise from 945:Equilateral triangle 902:equilateral triangle 399:-sided polygons for 4314:pentagonal polytope 4213:Uniform 10-polytope 3773:Fundamental convex 3395: 2677:regular apeirotopes 2531:dimensional analogy 2505:regular 4-polytopes 2115:{\displaystyle n-1} 1848:{\displaystyle n+1} 1436:. These are finite 1321:apart. Draw a line 1297:Begin with a point 1223: 1069:Begin with a point 995: 864:Begin with a point 775: 725:-dimensional cubic 443:. For example, the 391:-sided polygon for 83: 4183:Uniform 9-polytope 4133:Uniform 8-polytope 4083:Uniform 7-polytope 4040:Uniform 6-polytope 4010:Uniform 5-polytope 3970:Uniform polychoron 3933:Uniform polyhedron 3781:in dimensions 2–10 3702:D.M.Y. Sommerville 3448: 3381: 3341:2011-07-17 at the 3292:2007-10-28 at the 3285:See, for example, 3200:Regular polyhedron 3155: 3071: 3059: 3047: 3022:Archimedean solids 3002: 2819:abstract polytopes 2787:abstract polytopes 2740: 2720:Abstract polytopes 2472:. The sixth, the 2412:Alicia Boole Stott 2384: 2361:Great dodecahedron 2281:great dodecahedron 2261:Thomas Bradwardine 2112: 2086: 2066: 2046: 2025: 2005: 1985: 1965: 1945: 1925: 1905: 1885: 1865: 1845: 1819: 1799: 1779: 1755: 1735: 1707: 1669: 1641:gives the regular 1631: 1601: 1553: 1527:Exceptional types 1506: 1472: 1333:and orthogonal to 1221: 1172:(regular tetragon) 993: 773: 731:infinite polytopes 584:of the polyhedron. 552:regular polyhedron 331:{b, c, ..., y, z}. 327:{a, b, c, ..., y}, 312:abstract polytopes 283:(for example, the 275:(for example, the 81: 4347:Regular polytopes 4335: 4334: 4322:Polytope families 3779:uniform polytopes 3723:978-0-486-84248-6 3692:Science Awakening 3556:978-0-521-66405-9 3535:978-0-521-39490-1 3481:Regular Polytopes 3478:— (1973) . 3372:Coxeter, H. S. M. 3287:Euclid's Elements 3263:978-0-429-70681-3 3139:(a 4-dimensional 3031:Higher dimensions 2848:abstract polytope 2726:Abstract polytope 2493:measure polytopes 2489:regular simplices 2371: 2370: 2366:Great icosahedron 2285:great icosahedron 2249: 2248: 2089:{\displaystyle n} 2069:{\displaystyle P} 2049:{\displaystyle P} 2008:{\displaystyle n} 1988:{\displaystyle P} 1968:{\displaystyle n} 1928:{\displaystyle n} 1908:{\displaystyle P} 1888:{\displaystyle P} 1868:{\displaystyle n} 1782:{\displaystyle P} 1758:{\displaystyle n} 1738:{\displaystyle P} 1690:Exceptional type 1652:Exceptional type 1614:Exceptional type 1289: 1288: 1152:measure polytopes 1061: 1060: 921:regular simplices 856: 855: 769:Regular simplices 764:in 5 dimensions). 756:in 3 dimensions, 572:regular polyhedra 416:regular polyhedra 281:regular polyhedra 209: 208: 162:(shown here as a 105:, represented by 79: 78: 71: 4354: 4326:Regular polytope 3887: 3876: 3865: 3824: 3767: 3760: 3753: 3744: 3743: 3727: 3697: 3695: 3684: 3665: 3648: 3635: 3622: 3613: 3611: 3597: 3578: 3569: 3560: 3539: 3522:— (1991). 3518: 3506: 3499:— (1974). 3495: 3474: 3457: 3455: 3454: 3449: 3441: 3440: 3439: 3438: 3421: 3420: 3411: 3410: 3394: 3389: 3358: 3352: 3346: 3333: 3327: 3316: 3310: 3303: 3297: 3283: 3277: 3274: 3268: 3267: 3245: 3168:hyperbolic space 3141:spherical tiling 3055:Schlegel diagram 2971:Constructibility 2774:H. S. M. Coxeter 2713:complex polytope 2698:Complex polytope 2587:-polytope is an 2341: 2334: 2327: 2320: 2304: 2303: 2218: 2211: 2204: 2197: 2190: 2174: 2173: 2121: 2119: 2118: 2113: 2095: 2093: 2092: 2087: 2075: 2073: 2072: 2067: 2055: 2053: 2052: 2047: 2034: 2032: 2031: 2026: 2014: 2012: 2011: 2006: 1994: 1992: 1991: 1986: 1974: 1972: 1971: 1966: 1954: 1952: 1951: 1946: 1934: 1932: 1931: 1926: 1914: 1912: 1911: 1906: 1894: 1892: 1891: 1886: 1874: 1872: 1871: 1866: 1854: 1852: 1851: 1846: 1828: 1826: 1825: 1820: 1808: 1806: 1805: 1800: 1788: 1786: 1785: 1780: 1764: 1762: 1761: 1756: 1744: 1742: 1741: 1736: 1716: 1714: 1713: 1708: 1706: 1705: 1678: 1676: 1675: 1670: 1668: 1667: 1640: 1638: 1637: 1632: 1630: 1629: 1610: 1608: 1607: 1602: 1565:regular polygons 1562: 1560: 1559: 1554: 1543: 1542: 1518:measure polytope 1515: 1513: 1512: 1507: 1505: 1504: 1481: 1479: 1478: 1473: 1471: 1470: 1285: 1278: 1271: 1245: 1238: 1231: 1224: 1085:, orthogonal to 1057: 1050: 1043: 1017: 1010: 1003: 996: 947:(regular trigon) 852: 845: 838: 804: 797: 790: 783: 776: 714:({5,5/2,5}) and 687:regular polygons 478:Schläfli symbols 447:and the regular 385:regular polygons 353:Measure polytope 332: 328: 324: 297: 273:regular polygons 267: 253: 249: 239:-faces (for all 238: 217:regular polytope 195: 186: 173: 164:Schlegel diagram 161: 144: 135: 118: 111: 91: 84: 74: 67: 63: 60: 54: 49:this article by 40:inline citations 27: 26: 19: 4362: 4361: 4357: 4356: 4355: 4353: 4352: 4351: 4337: 4336: 4305: 4298: 4291: 4174: 4167: 4160: 4124: 4117: 4110: 4074: 4067: 3901:Regular polygon 3894: 3885: 3878: 3874: 3867: 3863: 3854: 3845: 3838: 3834: 3822: 3816: 3812: 3800: 3782: 3771: 3734: 3724: 3681: 3594: 3564:Euclid (1956). 3557: 3536: 3515: 3492: 3431: 3427: 3426: 3422: 3416: 3412: 3406: 3402: 3390: 3385: 3379: 3376: 3375: 3367: 3362: 3361: 3353: 3349: 3343:Wayback Machine 3334: 3330: 3317: 3313: 3304: 3300: 3294:Wayback Machine 3284: 3280: 3275: 3271: 3264: 3246: 3239: 3234: 3229: 3207: 3202: 3193: 3184: 3120:virtual reality 3057:) for tesseract 3033: 2980: 2953: 2948: 2915: 2902: 2877: 2842:The concept of 2840: 2815: 2728: 2722: 2700: 2694: 2669:Branko GrĂźnbaum 2661: 2655: 2516:Ludwig Schläfli 2497:cross polytopes 2400:Schläfli (1858) 2396:Schläfli (1855) 2392:Schläfli (1901) 2388:Ludwig Schläfli 2376: 2355: 2354:Great stellated 2348: 2347:Small stellated 2302: 2289:Augustin Cauchy 2279:discovered the 2265:Johannes Kepler 2256: 2179:Platonic solids 2167:Platonic solids 2141:Platonic solids 2133: 2128: 2101: 2098: 2097: 2081: 2078: 2077: 2061: 2058: 2057: 2041: 2038: 2037: 2020: 2017: 2016: 2000: 1997: 1996: 1980: 1977: 1976: 1960: 1957: 1956: 1940: 1937: 1936: 1920: 1917: 1916: 1900: 1897: 1896: 1880: 1877: 1876: 1860: 1857: 1856: 1834: 1831: 1830: 1814: 1811: 1810: 1794: 1791: 1790: 1774: 1771: 1770: 1750: 1747: 1746: 1730: 1727: 1726: 1701: 1697: 1695: 1692: 1691: 1663: 1659: 1657: 1654: 1653: 1625: 1621: 1619: 1616: 1615: 1572: 1569: 1568: 1538: 1534: 1532: 1529: 1528: 1500: 1496: 1494: 1491: 1490: 1466: 1462: 1460: 1457: 1456: 1430: 1424: 1416:-orthoplex has 1378:1. Line segment 1365:cross polytopes 1295: 1219: 1165:1. Line segment 1067: 991: 862: 771: 672:cross polytopes 645: 543:, so a regular 501:regular polygon 490:Ludwig Schläfli 486: 484:Schläfli symbol 480: 427:five dimensions 412:four dimensions 348:Regular simplex 338: 330: 326: 322: 319:Schläfli symbol 295: 259: 251: 240: 236: 196: 184: 177:cubic honeycomb 174: 159: 145: 133: 119: 109: 107:Schläfli symbol 92: 75: 64: 58: 55: 45:Please help to 44: 28: 24: 17: 12: 11: 5: 4360: 4350: 4349: 4333: 4332: 4317: 4316: 4307: 4303: 4296: 4289: 4285: 4276: 4259: 4250: 4239: 4238: 4236: 4234: 4229: 4220: 4215: 4209: 4208: 4206: 4204: 4199: 4190: 4185: 4179: 4178: 4176: 4172: 4165: 4158: 4154: 4149: 4140: 4135: 4129: 4128: 4126: 4122: 4115: 4108: 4104: 4099: 4090: 4085: 4079: 4078: 4076: 4072: 4065: 4061: 4056: 4047: 4042: 4036: 4035: 4033: 4031: 4026: 4017: 4012: 4006: 4005: 3996: 3991: 3986: 3977: 3972: 3966: 3965: 3956: 3954: 3949: 3940: 3935: 3929: 3928: 3923: 3918: 3913: 3908: 3903: 3897: 3896: 3892: 3888: 3883: 3872: 3861: 3852: 3843: 3836: 3830: 3820: 3814: 3808: 3802: 3796: 3790: 3784: 3783: 3772: 3770: 3769: 3762: 3755: 3747: 3742: 3741: 3733: 3732:External links 3730: 3729: 3728: 3722: 3698: 3685: 3679: 3666: 3653: 3636: 3623: 3614: 3598: 3592: 3579: 3570: 3561: 3555: 3540: 3534: 3519: 3513: 3496: 3490: 3475: 3447: 3444: 3437: 3434: 3430: 3425: 3419: 3415: 3409: 3405: 3401: 3398: 3393: 3388: 3384: 3366: 3363: 3360: 3359: 3347: 3328: 3326:, for example. 3311: 3298: 3278: 3276:Coxeter (1974) 3269: 3262: 3236: 3235: 3233: 3230: 3228: 3225: 3224: 3223: 3218: 3213: 3206: 3203: 3198:Main article: 3189:Main article: 3183: 3180: 3175:symmetry group 3032: 3029: 2979: 2976: 2952: 2949: 2947: 2944: 2937:may or may not 2911: 2905: 2904: 2898: 2873: 2839: 2836: 2814: 2811: 2724:Main article: 2721: 2718: 2704:complex number 2696:Main article: 2693: 2690: 2685:skew apeirogon 2657:Main article: 2654: 2651: 2639:Coxeter groups 2628: 2627: 2614: 2613: 2597: 2596: 2581: 2578:vertex figures 2574: 2418:Coxeter (1973) 2408:Reinhold Hoppe 2375: 2372: 2369: 2368: 2363: 2358: 2351: 2343: 2342: 2335: 2328: 2321: 2313: 2312: 2298:Main article: 2255: 2252: 2251: 2250: 2247: 2246: 2241: 2236: 2231: 2226: 2220: 2219: 2212: 2205: 2198: 2191: 2183: 2182: 2132: 2129: 2127: 2124: 2111: 2108: 2105: 2085: 2065: 2045: 2024: 2004: 1984: 1964: 1944: 1924: 1904: 1884: 1864: 1844: 1841: 1838: 1818: 1798: 1778: 1754: 1734: 1723: 1722: 1704: 1700: 1688: 1666: 1662: 1650: 1628: 1624: 1612: 1600: 1597: 1594: 1591: 1588: 1585: 1582: 1579: 1576: 1552: 1549: 1546: 1541: 1537: 1525: 1522:cross polytope 1503: 1499: 1487: 1469: 1465: 1438:Coxeter groups 1434:isometry group 1429: 1426: 1422: 1421: 1410: 1399: 1388: 1382: 1379: 1376: 1363:These are the 1344:. Draw a line 1291:Main article: 1287: 1286: 1279: 1272: 1264: 1263: 1258: 1253: 1247: 1246: 1239: 1232: 1218: 1215: 1214: 1213: 1202: 1191: 1180: 1173: 1166: 1163: 1150:These are the 1063:Main article: 1059: 1058: 1051: 1044: 1036: 1035: 1030: 1025: 1019: 1018: 1011: 1004: 990: 987: 986: 985: 974: 964: 954: 948: 941: 935: 919:These are the 872:at a distance 858:Main article: 854: 853: 846: 839: 832: 828: 827: 822: 817: 812: 806: 805: 798: 791: 784: 770: 767: 766: 765: 734: 719: 712:great 120-cell 708: 701: 690: 663:of {4, 3, 3}. 644: 641: 640: 639: 620: 585: 554:having faces { 548: 482:Main article: 479: 476: 381:two dimensions 363: 362: 359:Cross polytope 356: 350: 337: 334: 304:vertex figures 225:symmetry group 207: 206: 203:Petrie polygon 188: 187: 167: 137: 136: 112: 77: 76: 31: 29: 22: 15: 9: 6: 4: 3: 2: 4359: 4348: 4345: 4344: 4342: 4331: 4327: 4323: 4318: 4315: 4311: 4308: 4306: 4299: 4292: 4286: 4284: 4280: 4277: 4275: 4271: 4267: 4263: 4260: 4258: 4254: 4251: 4249: 4245: 4241: 4240: 4237: 4235: 4233: 4230: 4228: 4224: 4221: 4219: 4216: 4214: 4211: 4210: 4207: 4205: 4203: 4200: 4198: 4194: 4191: 4189: 4186: 4184: 4181: 4180: 4177: 4175: 4168: 4161: 4155: 4153: 4150: 4148: 4144: 4141: 4139: 4136: 4134: 4131: 4130: 4127: 4125: 4118: 4111: 4105: 4103: 4100: 4098: 4094: 4091: 4089: 4086: 4084: 4081: 4080: 4077: 4075: 4068: 4062: 4060: 4057: 4055: 4051: 4048: 4046: 4043: 4041: 4038: 4037: 4034: 4032: 4030: 4027: 4025: 4021: 4018: 4016: 4013: 4011: 4008: 4007: 4004: 4000: 3997: 3995: 3992: 3990: 3989:Demitesseract 3987: 3985: 3981: 3978: 3976: 3973: 3971: 3968: 3967: 3964: 3960: 3957: 3955: 3953: 3950: 3948: 3944: 3941: 3939: 3936: 3934: 3931: 3930: 3927: 3924: 3922: 3919: 3917: 3914: 3912: 3909: 3907: 3904: 3902: 3899: 3898: 3895: 3889: 3886: 3882: 3875: 3871: 3864: 3860: 3855: 3851: 3846: 3842: 3837: 3835: 3833: 3829: 3819: 3815: 3813: 3811: 3807: 3803: 3801: 3799: 3795: 3791: 3789: 3786: 3785: 3780: 3776: 3768: 3763: 3761: 3756: 3754: 3749: 3748: 3745: 3739: 3736: 3735: 3725: 3719: 3715: 3713: 3707: 3703: 3699: 3694: 3693: 3686: 3682: 3676: 3672: 3667: 3663: 3659: 3654: 3651: 3646: 3642: 3637: 3633: 3629: 3624: 3620: 3615: 3610: 3609: 3603: 3599: 3595: 3589: 3585: 3580: 3576: 3571: 3567: 3562: 3558: 3552: 3548: 3547: 3541: 3537: 3531: 3527: 3526: 3520: 3516: 3510: 3505: 3504: 3497: 3493: 3491:0-486-61480-8 3487: 3483: 3482: 3476: 3473: 3469: 3465: 3461: 3445: 3442: 3435: 3432: 3428: 3417: 3413: 3407: 3403: 3396: 3391: 3386: 3382: 3373: 3369: 3368: 3356: 3351: 3344: 3340: 3337: 3332: 3325: 3321: 3315: 3308: 3302: 3295: 3291: 3288: 3282: 3273: 3265: 3259: 3255: 3251: 3244: 3242: 3237: 3222: 3219: 3217: 3216:Johnson solid 3214: 3212: 3209: 3208: 3201: 3196: 3192: 3187: 3179: 3176: 3171: 3169: 3165: 3161: 3152: 3148: 3144: 3142: 3138: 3134: 3133:non-Euclidean 3130: 3126: 3121: 3116: 3114: 3110: 3105: 3099: 3097: 3093: 3089: 3085: 3079: 3075: 3068: 3063: 3056: 3051: 3045: 3041: 3037: 3028: 3025: 3023: 3018: 3013: 3009: 3007: 3000: 2996: 2992: 2988: 2985: 2975: 2972: 2968: 2966: 2962: 2958: 2946:Constructions 2943: 2940: 2938: 2933: 2931: 2927: 2923: 2919: 2914: 2910: 2901: 2897: 2893: 2889: 2885: 2881: 2876: 2872: 2869: 2868: 2867: 2865: 2861: 2857: 2853: 2849: 2845: 2844:vertex figure 2835: 2833: 2829: 2825: 2822: 2820: 2810: 2808: 2803: 2800: 2795: 2793: 2789: 2788: 2781: 2779: 2775: 2771: 2766: 2763: 2759: 2757: 2756:GrĂźnbaum 1976 2753: 2749: 2745: 2737: 2732: 2727: 2717: 2715: 2714: 2709: 2708:Hilbert space 2705: 2699: 2689: 2686: 2682: 2678: 2674: 2670: 2667:In the 1960s 2665: 2660: 2650: 2648: 2644: 2643:tessellations 2640: 2636: 2633: 2625: 2624: 2623: 2621: 2620: 2611: 2607: 2603: 2602: 2601: 2594: 2590: 2586: 2582: 2579: 2575: 2572: 2571: 2570: 2567: 2565: 2561: 2557: 2552: 2549: 2545: 2541: 2536: 2532: 2527: 2525: 2521: 2517: 2513: 2512:Arthur Cayley 2508: 2506: 2502: 2498: 2494: 2490: 2485: 2483: 2479: 2478:cuboctahedron 2475: 2471: 2467: 2463: 2459: 2455: 2451: 2447: 2443: 2439: 2435: 2431: 2427: 2423: 2419: 2415: 2413: 2409: 2405: 2404:Coxeter (1973 2401: 2397: 2393: 2389: 2380: 2367: 2364: 2362: 2359: 2357: 2352: 2350: 2345: 2344: 2340: 2333: 2326: 2319: 2314: 2311: 2310: 2305: 2301: 2296: 2294: 2290: 2287:in 1809, and 2286: 2282: 2278: 2277:Louis Poinsot 2274: 2270: 2266: 2262: 2245: 2242: 2240: 2237: 2235: 2232: 2230: 2227: 2225: 2222: 2221: 2217: 2210: 2203: 2196: 2189: 2184: 2181: 2180: 2175: 2172: 2171: 2170: 2168: 2164: 2163:number theory 2160: 2159: 2154: 2150: 2146: 2142: 2138: 2137:ancient Greek 2123: 2109: 2106: 2103: 2083: 2063: 2043: 2002: 1982: 1962: 1922: 1902: 1882: 1862: 1842: 1839: 1836: 1776: 1768: 1765:and take its 1752: 1745:of dimension 1732: 1720: 1702: 1698: 1689: 1686: 1682: 1664: 1660: 1651: 1648: 1644: 1626: 1622: 1613: 1598: 1595: 1592: 1589: 1586: 1583: 1580: 1577: 1574: 1566: 1547: 1539: 1535: 1526: 1523: 1519: 1516:, gives the 1501: 1497: 1488: 1485: 1467: 1463: 1454: 1453: 1452: 1450: 1445: 1443: 1439: 1435: 1425: 1419: 1415: 1411: 1408: 1404: 1400: 1397: 1393: 1389: 1387: 1383: 1380: 1377: 1374: 1373: 1372: 1370: 1366: 1361: 1359: 1355: 1351: 1347: 1343: 1340: 1336: 1332: 1329:, centred on 1328: 1324: 1320: 1316: 1312: 1308: 1304: 1300: 1294: 1284: 1280: 1277: 1273: 1270: 1266: 1265: 1262: 1259: 1257: 1254: 1252: 1249: 1248: 1244: 1237: 1230: 1225: 1211: 1207: 1203: 1200: 1196: 1192: 1189: 1185: 1181: 1178: 1174: 1171: 1167: 1164: 1161: 1160: 1159: 1157: 1153: 1148: 1146: 1143: 1139: 1135: 1131: 1127: 1123: 1119: 1115: 1111: 1108: 1104: 1100: 1096: 1092: 1088: 1084: 1080: 1076: 1072: 1066: 1056: 1052: 1049: 1045: 1042: 1038: 1037: 1034: 1031: 1029: 1026: 1024: 1021: 1020: 1016: 1009: 1002: 997: 983: 980:-simplex has 979: 975: 972: 969: 965: 962: 959: 955: 953: 949: 946: 942: 940: 936: 934: 930: 929: 928: 926: 922: 917: 915: 911: 907: 904:. Mark point 903: 899: 895: 891: 887: 884:in a second, 883: 880:. Mark point 879: 875: 871: 868:. Mark point 867: 861: 851: 847: 844: 840: 837: 833: 830: 829: 826: 823: 821: 818: 816: 813: 811: 808: 807: 803: 796: 789: 782: 777: 763: 759: 755: 751: 747: 743: 739: 735: 732: 728: 724: 720: 717: 713: 709: 706: 702: 700:, {3,3,...,3} 699: 695: 691: 688: 684: 683: 682: 680: 675: 673: 669: 664: 662: 658: 657:vertex figure 653: 650: 638:}. And so on. 637: 633: 629: 625: 621: 618: 614: 610: 606: 602: 598: 594: 590: 586: 583: 582: 581:vertex figure 577: 573: 569: 565: 561: 557: 553: 549: 546: 542: 538: 534: 530: 526: 522: 518: 514: 510: 506: 502: 499: 495: 494: 493: 491: 485: 475: 472: 470: 466: 462: 458: 454: 450: 446: 442: 437: 435: 432:See also the 430: 428: 423: 421: 417: 413: 409: 404: 402: 398: 394: 390: 386: 382: 377: 375: 371: 370:one dimension 366: 360: 357: 354: 351: 349: 346: 345: 344: 341: 333: 320: 315: 313: 309: 305: 301: 292: 290: 286: 282: 278: 274: 269: 266: 262: 257: 248: 244: 234: 230: 226: 222: 218: 214: 204: 200: 194: 189: 182: 178: 172: 168: 165: 157: 153: 149: 143: 139: 131: 127: 123: 117: 113: 108: 104: 100: 96: 90: 86: 73: 70: 62: 52: 48: 42: 41: 35: 30: 21: 20: 4325: 4309: 4278: 4269: 4261: 4252: 4243: 4223:10-orthoplex 3959:Dodecahedron 3880: 3869: 3858: 3849: 3840: 3831: 3827: 3817: 3809: 3805: 3797: 3793: 3774: 3711: 3709: 3691: 3670: 3661: 3657: 3649: 3644: 3640: 3631: 3627: 3618: 3607: 3602:McMullen, P. 3583: 3574: 3565: 3545: 3524: 3502: 3480: 3466:(1): 21–25, 3463: 3459: 3365:Bibliography 3350: 3331: 3314: 3301: 3281: 3272: 3253: 3194: 3185: 3172: 3164:tessellation 3156: 3117: 3100: 3092:Coxeter 1973 3084:orthographic 3080: 3076: 3072: 3026: 3014: 3010: 3006:fold-out net 3003: 2983: 2981: 2969: 2964: 2960: 2954: 2941: 2936: 2934: 2929: 2925: 2921: 2917: 2912: 2908: 2906: 2899: 2895: 2891: 2887: 2883: 2879: 2874: 2870: 2863: 2862:, including 2859: 2855: 2851: 2843: 2841: 2832:All polygons 2831: 2830: 2826: 2823: 2816: 2804: 2798: 2796: 2791: 2785: 2782: 2767: 2764: 2760: 2751: 2741: 2711: 2701: 2673:polystromata 2672: 2666: 2662: 2629: 2617: 2615: 2609: 2605: 2598: 2592: 2588: 2584: 2568: 2558:such as the 2553: 2528: 2509: 2486: 2462:dodecahedron 2416: 2385: 2356:dodecahedron 2349:dodecahedron 2307: 2267:studied the 2257: 2239:Dodecahedron 2177: 2156: 2134: 1724: 1643:dodecahedron 1449:Coxeter 1935 1446: 1431: 1423: 1417: 1413: 1406: 1395: 1368: 1364: 1362: 1353: 1349: 1345: 1341: 1334: 1330: 1326: 1322: 1318: 1314: 1310: 1306: 1302: 1298: 1296: 1209: 1205: 1198: 1187: 1155: 1151: 1149: 1144: 1140:to form the 1137: 1133: 1129: 1125: 1121: 1117: 1113: 1109: 1105:, to form a 1102: 1098: 1094: 1090: 1086: 1082: 1078: 1077:at distance 1074: 1070: 1068: 984:+1 vertices. 981: 977: 970: 960: 939:Line segment 924: 920: 918: 909: 905: 897: 893: 889: 881: 878:line segment 873: 869: 865: 863: 810:Line segment 722: 721:All regular 703:The regular 693: 692:All regular 676: 665: 654: 646: 635: 631: 627: 623: 616: 612: 608: 604: 600: 596: 592: 588: 579: 575: 570:}. The nine 567: 563: 559: 555: 536: 532: 528: 524: 520: 519:which winds 517:star polygon 512: 508: 504: 487: 473: 453:dodecahedron 438: 431: 424: 405: 400: 396: 392: 388: 378: 374:line segment 367: 364: 342: 339: 321:of the form 316: 293: 270: 264: 260: 246: 242: 229:transitively 216: 210: 181:tessellation 122:dodecahedron 65: 56: 37: 4232:10-demicube 4193:9-orthoplex 4143:8-orthoplex 4093:7-orthoplex 4050:6-orthoplex 4020:5-orthoplex 3975:Pentachoron 3963:Icosahedron 3938:Tetrahedron 3088:perspective 2999:icosahedron 2799:realization 2792:containment 2470:icosahedron 2446:4-orthoplex 2430:tetrahedron 2244:Icosahedron 2224:Tetrahedron 1647:icosahedron 1409:5-orthoplex 1398:4-orthoplex 1384:3. Regular 1369:orthoplexes 1325:of length 2 1309:a distance 966:5. Regular 958:pentachoron 956:4. Regular 952:tetrahedron 950:3. Regular 914:tetrahedron 900:to form an 825:Pentachoron 820:Tetrahedron 762:{3,3,4,3,3} 679:palindromic 465:tetrahedral 457:icosahedron 420:4-polytopes 361:(Orthoplex) 355:(Hypercube) 213:mathematics 51:introducing 4218:10-simplex 4202:9-demicube 4152:8-demicube 4102:7-demicube 4059:6-demicube 4029:5-demicube 3943:Octahedron 3714:Dimensions 3680:0471861685 3647:: 269–301. 3634:: 359–394. 3593:0792330161 3514:052120125X 3227:References 2681:infinitely 2647:chessboard 2464:, and the 2454:octahedron 2234:Octahedron 2149:Theaetetus 2145:Pythagoras 1717:gives the 1679:gives the 1403:Pentacross 1386:octahedron 1358:octahedron 1256:Octahedron 1208:-cube has 1156:hypercubes 886:orthogonal 727:honeycombs 449:octahedron 175:A regular 152:polychoron 146:A regular 126:polyhedron 120:A regular 93:A regular 34:references 4266:orthoplex 4188:9-simplex 4138:8-simplex 4088:7-simplex 4045:6-simplex 4015:5-simplex 3984:Tesseract 3704:(2020) . 3546:Polyhedra 3129:Euclidean 3044:tesseract 2982:Euclid's 2978:Polyhedra 2748:self-dual 2548:tesseract 2540:tesseract 2535:tesseract 2520:tesseract 2452:) to the 2440:) to the 2438:tesseract 2434:hypercube 2426:4-simplex 2107:− 2023:Δ 1943:Δ 1817:Δ 1797:Δ 1563:give the 1420:vertices. 1293:Orthoplex 1212:vertices. 1195:Penteract 1184:Tesseract 1065:Hypercube 1033:Tesseract 973:5-simplex 968:hexateron 963:4-simplex 925:simplexes 758:{5,3,3,5} 698:simplexes 578:} is the 547:is {5/2}. 545:pentagram 531:}, where 289:aesthetic 256:dimension 59:July 2014 4341:Category 4320:Topics: 4283:demicube 4248:polytope 4242:Uniform 4003:600-cell 3999:120-cell 3952:Demicube 3926:Pentagon 3906:Triangle 3664:: 1–237. 3566:Elements 3339:Archived 3290:Archived 3205:See also 3113:hologram 3109:CAT scan 3104:animated 2984:Elements 2951:Polygons 2736:Hemicube 2632:symmetry 2522:and the 2480:and the 2466:600-cell 2458:120-cell 2271:and the 2158:Elements 1685:600-cell 1683:and the 1681:120-cell 1520:and the 1375:0. Point 1162:0. Point 1145:ABCDEFGH 815:Triangle 541:co-prime 441:symmetry 308:vertices 250:, where 221:polytope 185:{4,3,4}. 160:{5,3,3}. 148:120-cell 95:pentagon 4257:simplex 4227:10-cube 3994:24-cell 3980:16-cell 3921:Hexagon 3775:regular 3320:origami 3191:Polygon 3067:24-cell 2924:-face, 2778:57-cell 2770:11-cell 2744:11-cell 2564:11-cell 2562:or the 2560:57-cell 2544:24-cell 2524:24-cell 2474:24-cell 2468:to the 2460:to the 2450:16-cell 1719:24-cell 1484:simplex 1412:... An 1392:16-cell 1261:16-cell 1204:... An 1089:, from 976:... An 860:Simplex 831:  754:{3,6,3} 750:{6,3,6} 746:{3,5,3} 742:{5,3,5} 738:{4,4,4} 705:24-cell 668:measure 595:} with 558:} with 515:-sided 503:having 254:is the 231:on its 99:polygon 47:improve 4197:9-cube 4147:8-cube 4097:7-cube 4054:6-cube 4024:5-cube 3911:Square 3788:Family 3720:  3677:  3590:  3553:  3532:  3511:  3488:  3260:  3137:sphere 3017:klikko 2907:where 2754:face ( 2635:groups 2542:. The 2456:, the 2444:, the 2432:, the 2153:Euclid 1567:(with 1339:square 1251:Square 1201:5-cube 1190:4-cube 1170:Square 1107:square 1023:Square 752:, and 689:, {a}. 498:convex 372:, the 300:facets 277:square 223:whose 199:8-cube 134:{5,3}. 36:, but 3916:p-gon 3232:Notes 1489:Type 1455:Type 1317:and 2 1313:from 933:Point 408:three 233:flags 227:acts 219:is a 179:is a 156:cells 150:is a 130:faces 124:is a 103:edges 97:is a 4274:cube 3947:Cube 3777:and 3718:ISBN 3675:ISBN 3588:ISBN 3551:ISBN 3530:ISBN 3509:ISBN 3486:ISBN 3324:here 3307:here 3258:ISBN 3160:UIUC 3042:for 2997:for 2752:same 2734:The 2619:flag 2514:and 2495:and 2442:cube 2436:(or 2398:and 2283:and 2229:Cube 2076:has 1829:has 1645:and 1352:and 1342:ACBD 1305:and 1177:Cube 1142:cube 1120:and 1110:ABCD 1028:Cube 896:and 710:The 685:All 670:and 666:The 661:cell 655:The 649:dual 647:The 539:are 535:and 467:and 461:dual 455:and 445:cube 418:and 410:and 285:cube 241:0 ≤ 215:, a 110:{5}. 3823:(p) 3468:doi 3458:", 3166:of 3143:). 3098:). 3086:or 3040:Net 2995:Net 2882:= { 2604:An 1367:or 1346:EOF 1323:COD 1193:5. 1182:4. 1175:3. 1168:2. 1154:or 1101:to 1093:to 943:2. 937:1. 931:0. 923:or 425:In 422:. 406:In 379:In 368:In 211:In 4343:: 4328:• 4324:• 4304:21 4300:• 4297:k1 4293:• 4290:k2 4268:• 4225:• 4195:• 4173:21 4169:• 4166:41 4162:• 4159:42 4145:• 4123:21 4119:• 4116:31 4112:• 4109:32 4095:• 4073:21 4069:• 4066:22 4052:• 4022:• 4001:• 3982:• 3961:• 3945:• 3877:/ 3866:/ 3856:/ 3847:/ 3825:/ 3708:. 3662:38 3660:. 3643:. 3632:20 3630:. 3464:10 3462:, 3357:). 3240:^ 2894:≤ 2890:≤ 2886:| 2878:/ 2772:, 2716:. 2702:A 2526:. 2491:, 2295:. 2169:. 1611:), 1418:2n 1407:or 1405:) 1396:or 1394:) 1354:CD 1350:AB 1335:AB 1199:or 1188:or 1122:BC 1118:AB 1087:AB 971:or 961:or 748:, 744:. 740:, 634:, 630:, 626:, 619:}. 615:, 607:, 603:, 591:, 566:, 550:A 496:A 471:. 436:. 314:. 268:. 263:≤ 245:≤ 205:) 166:) 4312:- 4310:n 4302:k 4295:2 4288:1 4281:- 4279:n 4272:- 4270:n 4264:- 4262:n 4255:- 4253:n 4246:- 4244:n 4171:4 4164:2 4157:1 4121:3 4114:2 4107:1 4071:2 4064:1 3893:n 3891:H 3884:2 3881:G 3873:4 3870:F 3862:8 3859:E 3853:7 3850:E 3844:6 3841:E 3832:n 3828:D 3821:2 3818:I 3810:n 3806:B 3798:n 3794:A 3766:e 3759:t 3752:v 3726:. 3712:n 3683:. 3650:3 3645:2 3596:. 3559:. 3538:. 3517:. 3494:. 3470:: 3446:1 3443:= 3436:j 3433:i 3429:k 3424:) 3418:j 3414:r 3408:i 3404:r 3400:( 3397:= 3392:2 3387:i 3383:r 3345:. 3309:. 3296:. 3266:. 3069:. 2965:n 2961:n 2930:i 2926:i 2922:i 2918:n 2913:n 2909:F 2903:} 2900:n 2896:F 2892:F 2888:V 2884:F 2880:V 2875:n 2871:F 2864:V 2860:V 2856:V 2852:n 2610:n 2606:n 2593:n 2589:n 2585:n 2110:1 2104:n 2084:n 2064:P 2044:P 2003:n 1983:P 1963:n 1923:n 1903:P 1883:P 1863:n 1843:1 1840:+ 1837:n 1777:P 1753:n 1733:P 1703:4 1699:F 1687:, 1665:4 1661:H 1627:3 1623:H 1599:. 1596:. 1593:. 1590:, 1587:4 1584:, 1581:3 1578:= 1575:n 1551:) 1548:n 1545:( 1540:2 1536:I 1502:n 1498:B 1486:, 1468:n 1464:A 1414:n 1331:O 1327:r 1319:r 1315:O 1311:r 1307:B 1303:A 1299:O 1210:2 1206:n 1138:H 1136:, 1134:G 1132:, 1130:F 1128:, 1126:E 1114:r 1103:D 1099:A 1095:C 1091:B 1083:r 1079:r 1075:B 1071:A 982:n 978:n 910:r 906:D 898:B 894:A 890:r 882:C 874:r 870:B 866:A 733:. 723:n 696:- 694:n 636:r 632:q 628:p 624:n 617:q 613:p 609:q 605:p 601:n 597:q 593:p 589:n 576:p 568:p 564:n 560:p 556:n 537:m 533:n 529:m 527:/ 525:n 521:m 513:n 509:n 505:n 401:n 397:n 393:n 389:n 296:n 265:n 261:j 252:n 247:n 243:j 237:j 72:) 66:( 61:) 57:( 43:.

Index

references
inline citations
improve
introducing
Learn how and when to remove this message

pentagon
polygon
edges
Schläfli symbol

dodecahedron
polyhedron
faces

120-cell
polychoron
cells
Schlegel diagram

cubic honeycomb
tessellation

8-cube
Petrie polygon
mathematics
polytope
symmetry group
transitively
flags

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

↑