Knowledge

Semicircle

Source 📝

333: 199: 191: 47: 655: 301:, and then connecting their common endpoint to the semicircle with a segment perpendicular to the diameter. The length of the resulting segment is the geometric mean. This can be proven by applying the 644: 556: 305:
to three similar right triangles, each having as vertices the point where the perpendicular touches the semicircle and two of the three endpoints of the segments of lengths
471: 419:
to their neighbours, and to the x-axis at these points. Semicircles joining adjacent points on the x-axis pass through the points of contact at right angles.
379:, arranged in order of increasing size. With a restricted definition, each Farey sequence starts with the value 0, denoted by the fraction 320:
of a rectangle. The side length of the square is the geometric mean of the side lengths of the rectangle. More generally, it is used as a
324:
in a general method for transforming any polygonal shape into a similar copy of itself with the area of any other given polygonal shape.
316:
The construction of the geometric mean can be used to transform any rectangle into a square of the same area, a problem called the
255: 567: 479: 343: 715: 803: 332: 17: 700: 745: 705: 734: 123: 430: 317: 163:
at each of the endpoints of the semicircle and the third vertex elsewhere on the semicircle is a
226: 137:
that also includes the diameter segment from one end of the arc to the other or to the half-
207: 142: 266:
means of two lengths using straight-edge and compass. For a semicircle with a diameter of
8: 321: 302: 230: 202: 127: 104: 149: 31: 776: 674:
bounded by three semicircles connected at their endpoints, all on the same side of a
160: 133:
In non-technical usage, the term "semicircle" is sometimes used to refer to either a
671: 340:
from 1 to 9. Each semicircle intersects its corresponding circles at right angles.
179: 156: 473:
on the diameter between its endpoints and which is entirely concave from below is
368: 259: 214: 138: 779: 198: 757: 352: 290: 263: 234: 164: 797: 675: 175: 695: 134: 112: 190: 412: 372: 168: 92: 784: 78: 336:
Comparison of Ford circles and a Farey diagram with semicircles for
683: 364: 360: 293:
can be found by dividing the diameter into two segments of lengths
213:
PR is the diameter of a circle centered on O; its radius AO is the
153: 96: 46: 710: 667: 416: 119: 275: 108: 194:
Construction of a square with the same area as a given oblong
182:
at the center of the circle containing the given semicircle.
347:
hover over a circle or curve to highlight it and its terms.
54: 654: 561:
If it is entirely concave from above, the equation is
639:{\displaystyle y=y_{0}-{\sqrt {r^{2}-(x-x_{0})^{2}}}} 570: 551:{\displaystyle y=y_{0}+{\sqrt {r^{2}-(x-x_{0})^{2}}}} 482: 433: 774: 638: 550: 465: 185: 795: 145:that further includes all the interior points. 286:(since the radius is half of the diameter). 427:The equation of a semicircle with midpoint 746:Euclid's Elements, Book VI, Proposition 25 735:Euclid's Elements, Book VI, Proposition 13 653: 331: 197: 189: 14: 796: 174:All lines intersecting the semicircle 775: 126:). It only has one line of symmetry ( 24: 115:that measures 180° (equivalently, 25: 815: 768: 327: 45: 107:of points that forms half of a 750: 739: 728: 716:Wigner semicircle distribution 625: 605: 537: 517: 460: 434: 186:Arithmetic and geometric means 13: 1: 721: 466:{\displaystyle (x_{0},y_{0})} 395:, and ends with the fraction 141:, which is a two-dimensional 254:A semicircle can be used to 7: 689: 422: 10: 820: 649: 278:is the arithmetic mean of 29: 77: 53: 44: 39: 30:For the music album, see 701:Archimedes' twin circles 706:Archimedes' quadruplets 159:in a semicircle with a 95:(and more specifically 682:) that contains their 663: 640: 552: 467: 375:less than or equal to 363:of completely reduced 348: 251: 227:geometric mean theorem 195: 657: 641: 553: 468: 335: 201: 193: 171:at the third vertex. 103:is a one-dimensional 568: 480: 431: 274:, the length of its 804:Elementary geometry 670:is a region in the 415:can be constructed 303:Pythagorean theorem 203:Proof without words 128:reflection symmetry 777:Weisstein, Eric W. 664: 636: 548: 463: 349: 252: 196: 32:Semicircle (album) 634: 546: 229:, triangle PGR's 89: 88: 16:(Redirected from 811: 790: 789: 762: 761: 754: 748: 743: 737: 732: 645: 643: 642: 637: 635: 633: 632: 623: 622: 601: 600: 591: 586: 585: 557: 555: 554: 549: 547: 545: 544: 535: 534: 513: 512: 503: 498: 497: 472: 470: 469: 464: 459: 458: 446: 445: 410: 408: 407: 404: 401: 394: 392: 391: 388: 385: 346: 250: 247: 237:. For any ratio 211: 208:AM–GM inequality 143:geometric region 118: 85: 73: 71: 70: 67: 64: 49: 37: 36: 21: 819: 818: 814: 813: 812: 810: 809: 808: 794: 793: 771: 766: 765: 756: 755: 751: 744: 740: 733: 729: 724: 692: 652: 628: 624: 618: 614: 596: 592: 590: 581: 577: 569: 566: 565: 540: 536: 530: 526: 508: 504: 502: 493: 489: 481: 478: 477: 454: 450: 441: 437: 432: 429: 428: 425: 405: 402: 399: 398: 396: 389: 386: 383: 382: 380: 369:in lowest terms 341: 330: 248: 238: 215:arithmetic mean 206: 188: 176:perpendicularly 150:Thales' theorem 116: 83: 68: 65: 62: 61: 59: 35: 28: 27:Geometric shape 23: 22: 15: 12: 11: 5: 817: 807: 806: 792: 791: 770: 769:External links 767: 764: 763: 749: 738: 726: 725: 723: 720: 719: 718: 713: 708: 703: 698: 691: 688: 651: 648: 647: 646: 631: 627: 621: 617: 613: 610: 607: 604: 599: 595: 589: 584: 580: 576: 573: 559: 558: 543: 539: 533: 529: 525: 522: 519: 516: 511: 507: 501: 496: 492: 488: 485: 462: 457: 453: 449: 444: 440: 436: 424: 421: 353:Farey sequence 344:the SVG image, 329: 326: 291:geometric mean 249:AO ≥ GQ. 235:geometric mean 212: 187: 184: 165:right triangle 87: 86: 81: 75: 74: 57: 51: 50: 42: 41: 26: 9: 6: 4: 3: 2: 816: 805: 802: 801: 799: 787: 786: 781: 778: 773: 772: 759: 758:"Ford Circle" 753: 747: 742: 736: 731: 727: 717: 714: 712: 709: 707: 704: 702: 699: 697: 694: 693: 687: 685: 681: 677: 676:straight line 673: 669: 662:(grey region) 661: 656: 629: 619: 615: 611: 608: 602: 597: 593: 587: 582: 578: 574: 571: 564: 563: 562: 541: 531: 527: 523: 520: 514: 509: 505: 499: 494: 490: 486: 483: 476: 475: 474: 455: 451: 447: 442: 438: 420: 418: 414: 378: 374: 370: 366: 362: 358: 354: 345: 339: 334: 328:Farey diagram 325: 323: 319: 314: 312: 308: 304: 300: 296: 292: 287: 285: 281: 277: 273: 269: 265: 261: 257: 245: 241: 236: 232: 228: 224: 220: 216: 209: 204: 200: 192: 183: 181: 177: 172: 170: 166: 162: 158: 155: 151: 146: 144: 140: 136: 131: 129: 125: 121: 114: 110: 106: 102: 98: 94: 82: 80: 76: 58: 56: 52: 48: 43: 38: 33: 19: 783: 780:"Semicircle" 752: 741: 730: 696:Amphitheater 679: 665: 659: 560: 426: 413:Ford circles 376: 373:denominators 356: 350: 337: 315: 310: 306: 298: 294: 288: 283: 279: 271: 267: 253: 243: 239: 225:. Using the 222: 218: 173: 147: 135:closed curve 132: 113:circular arc 100: 90: 18:Semicircular 367:which when 169:right angle 93:mathematics 722:References 318:quadrature 260:arithmetic 233:GQ is the 180:concurrent 111:. It is a 101:semicircle 40:Semicircle 785:MathWorld 684:diameters 612:− 603:− 588:− 524:− 515:− 365:fractions 355:of order 264:geometric 256:construct 167:, with a 157:inscribed 124:half-turn 79:Perimeter 798:Category 690:See also 680:baseline 423:Equation 361:sequence 231:altitude 154:triangle 97:geometry 711:Salinon 668:arbelos 660:arbelos 650:Arbelos 417:tangent 409:⁠ 397:⁠ 393:⁠ 381:⁠ 359:is the 205:of the 122:, or a 120:radians 72:⁠ 60:⁠ 276:radius 161:vertex 152:, any 109:circle 84:(π+2)r 678:(the 672:plane 371:have 322:lemma 105:locus 99:), a 351:The 309:and 297:and 289:The 282:and 262:and 258:the 221:and 178:are 139:disk 55:Area 666:An 658:An 342:In 217:of 148:By 130:). 91:In 800:: 782:. 686:. 411:. 313:. 270:+ 63:πr 788:. 760:. 630:2 626:) 620:0 616:x 609:x 606:( 598:2 594:r 583:0 579:y 575:= 572:y 542:2 538:) 532:0 528:x 521:x 518:( 510:2 506:r 500:+ 495:0 491:y 487:= 484:y 461:) 456:0 452:y 448:, 443:0 439:x 435:( 406:1 403:/ 400:1 390:1 387:/ 384:0 377:n 357:n 338:n 311:b 307:a 299:b 295:a 284:b 280:a 272:b 268:a 246:, 244:b 242:: 240:a 223:b 219:a 210:: 117:π 69:2 66:/ 34:. 20:)

Index

Semicircular
Semicircle (album)

Area
Perimeter
mathematics
geometry
locus
circle
circular arc
radians
half-turn
reflection symmetry
closed curve
disk
geometric region
Thales' theorem
triangle
inscribed
vertex
right triangle
right angle
perpendicularly
concurrent


Proof without words
AM–GM inequality
arithmetic mean
geometric mean theorem

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