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Edge (geometry)

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or edge-skeleton, a graph whose vertices are the geometric vertices of the polyhedron and whose edges correspond to the geometric edges. Conversely, the graphs that are skeletons of three-dimensional polyhedra can be characterized by
311:-dimensional convex polytope. Similarly, in a polyhedron, exactly two two-dimensional faces meet at every edge, while in higher dimensional polytopes three or more two-dimensional faces meet at every edge. 101: 254: 41: 181:, unlike polygon and polyhedron edges which have a concrete geometric representation as a line segment. However, any polyhedron can be represented by its 77: 157:(or polyhedron sides) meet. A segment joining two vertices while passing through the interior or exterior is not an edge but instead is called a 61: 691: 585: 476: 420: 412: 280: 686: 365: − 3)-dimensional feature. Thus, the edges of a polygon are its facets, the edges of a 3-dimensional 191: 178: 300: 283:. Thus the number of edges is 2 less than the sum of the numbers of vertices and faces. For example, a 187: 402: 210: 174: 31: 696: 617: 659: 640: 581: 513: 492: 472: 462: 416: 366: 296: 264: 218: 206: 134: 68: 48: 466: 406: 609: 575: 546: 347: 325: 560: 508: 556: 526: 504: 357: 320: 284: 276: 154: 84: 496: 601: 680: 604:(1986), "Constructing higher-dimensional convex hulls at logarithmic cost per face", 382: 17: 662: 606:
Proceedings of the Eighteenth Annual ACM Symposium on Theory of Computing (STOC '86)
499:(2000), "Bridges between geometry and graph theory", in Gorini, Catherine A. (ed.), 153:. In a polyhedron or more generally a polytope, an edge is a line segment where two 621: 503:, MAA Notes, vol. 53, Washington, DC: Math. Assoc. America, pp. 174–194, 194: 170: 130: 468:
Shaping Space: Exploring Polyhedra in Nature, Art, and the Geometrical Imagination
643: 530: 449: 149:. In a polygon, an edge is a line segment on the boundary, and is often called a 436: 370: 182: 142: 108: 88: 667: 648: 551: 112: 338: 158: 146: 122: 52: 613: 138: 27:
Line segment joining two adjacent vertices in a polygon or polytope
92: 221: 415:, vol. 152, Springer, Definition 2.1, p. 51, 248: 107:Every edge is shared by three or more faces in a 287:has 8 vertices and 6 faces, and hence 12 edges. 531:"On the graph structure of convex polyhedra in 47:Three edges AB, BC, and CA, each between two 8: 355: − 2)-dimensional feature, and a 580:, Cambridge University Press, p. 1, 550: 220: 345: − 1)-dimensional features, a 394: 37: 295:In a polygon, two edges meet at each 177:is an abstract object connecting two 7: 512:. See in particular Theorem 3, 67:A polygon is bounded by edges; this 369:are its ridges, and the edges of a 319:In the theory of high-dimensional 111:, as seen in this projection of a 25: 307:edges meet at every vertex of a 100: 76: 60: 40: 201:Number of edges in a polyhedron 539:Pacific Journal of Mathematics 1: 574:Wenninger, Magnus J. (1974), 413:Graduate Texts in Mathematics 279:. This equation is known as 271:is the number of edges, and 83:Every edge is shared by two 291:Incidences with other faces 165:Relation to edges in graphs 713: 692:Multi-dimensional geometry 452:". From Wolfram MathWorld. 439:". From Wolfram MathWorld. 281:Euler's polyhedron formula 29: 471:, Springer, p. 81, 249:{\displaystyle V-E+F=2,} 145:, or higher-dimensional 129:is a particular type of 30:Not to be confused with 552:10.2140/pjm.1961.11.431 315:Alternative terminology 371:4-dimensional polytope 250: 408:Lectures on Polytopes 299:; more generally, by 251: 190:as being exactly the 18:Side (plane geometry) 608:, pp. 404–413, 448:Weisstein, Eric W. " 435:Weisstein, Eric W. " 219: 211:Euler characteristic 687:Elementary geometry 614:10.1145/12130.12172 32:Edge (graph theory) 660:Weisstein, Eric W. 641:Weisstein, Eric W. 463:Senechal, Marjorie 403:Ziegler, Günter M. 301:Balinski's theorem 246: 192:3-vertex-connected 188:Steinitz's theorem 663:"Polyhedral edge" 577:Polyhedron Models 367:convex polyhedron 275:is the number of 263:is the number of 207:convex polyhedron 16:(Redirected from 704: 673: 672: 654: 653: 644:"Polygonal edge" 626: 624: 598: 592: 590: 571: 565: 563: 554: 523: 517: 511: 501:Geometry at work 489: 483: 481: 459: 453: 446: 440: 433: 427: 425: 399: 321:convex polytopes 255: 253: 252: 247: 104: 80: 64: 44: 21: 712: 711: 707: 706: 705: 703: 702: 701: 677: 676: 658: 657: 639: 638: 635: 630: 629: 602:Seidel, Raimund 600: 599: 595: 588: 573: 572: 568: 527:Balinski, M. L. 525: 524: 520: 493:Pisanski, Tomaž 491: 490: 486: 479: 461: 460: 456: 447: 443: 434: 430: 423: 401: 400: 396: 391: 379: 373:are its peaks. 341:is one of its ( 317: 293: 217: 216: 209:'s surface has 203: 167: 119: 116: 105: 96: 81: 72: 65: 56: 45: 35: 28: 23: 22: 15: 12: 11: 5: 710: 708: 700: 699: 694: 689: 679: 678: 675: 674: 655: 634: 633:External links 631: 628: 627: 593: 586: 566: 545:(2): 431–434, 518: 484: 477: 454: 441: 428: 421: 393: 392: 390: 387: 386: 385: 378: 375: 316: 313: 292: 289: 257: 256: 245: 242: 239: 236: 233: 230: 227: 224: 202: 199: 179:graph vertices 166: 163: 118: 117: 106: 99: 97: 82: 75: 73: 66: 59: 57: 46: 39: 36: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 709: 698: 695: 693: 690: 688: 685: 684: 682: 670: 669: 664: 661: 656: 651: 650: 645: 642: 637: 636: 632: 623: 619: 615: 611: 607: 603: 597: 594: 589: 587:9780521098595 583: 579: 578: 570: 567: 562: 558: 553: 548: 544: 540: 536: 534: 528: 522: 519: 515: 510: 506: 502: 498: 497:Randić, Milan 494: 488: 485: 480: 478:9780387927145 474: 470: 469: 464: 458: 455: 451: 450:Polytope Edge 445: 442: 438: 432: 429: 424: 422:9780387943657 418: 414: 410: 409: 404: 398: 395: 388: 384: 383:Extended side 381: 380: 376: 374: 372: 368: 364: 360: 359: 354: 350: 349: 344: 340: 337:-dimensional 336: 332: 328: 327: 322: 314: 312: 310: 306: 302: 298: 290: 288: 286: 282: 278: 274: 270: 266: 262: 243: 240: 237: 234: 231: 228: 225: 222: 215: 214: 213: 212: 208: 200: 198: 196: 195:planar graphs 193: 189: 184: 180: 176: 172: 164: 162: 160: 156: 152: 148: 144: 140: 136: 132: 128: 124: 114: 110: 103: 98: 94: 90: 86: 79: 74: 70: 63: 58: 54: 50: 43: 38: 33: 19: 666: 647: 605: 596: 576: 569: 542: 538: 532: 521: 500: 487: 467: 457: 444: 437:Polygon Edge 431: 407: 397: 362: 356: 352: 346: 342: 334: 330: 324: 318: 308: 304: 294: 272: 268: 260: 258: 204: 171:graph theory 168: 151:polygon side 150: 133:joining two 131:line segment 126: 120: 91:, like this 71:has 4 edges. 514:p. 176 303:, at least 681:Categories 389:References 143:polyhedron 109:4-polytope 89:polyhedron 697:Polytopes 668:MathWorld 649:MathWorld 226:− 113:tesseract 529:(1961), 465:(2013), 405:(1995), 377:See also 339:polytope 265:vertices 183:skeleton 159:diagonal 147:polytope 135:vertices 123:geometry 53:triangle 49:vertices 622:8342016 561:0126765 535:-space" 509:1782654 139:polygon 620:  584:  559:  507:  475:  419:  361:is a ( 351:is a ( 297:vertex 259:where 69:square 618:S2CID 348:ridge 333:of a 326:facet 277:faces 173:, an 155:faces 137:in a 125:, an 87:in a 85:faces 51:of a 582:ISBN 473:ISBN 417:ISBN 358:peak 331:side 323:, a 285:cube 205:Any 175:edge 127:edge 93:cube 610:doi 547:doi 329:or 169:In 121:In 683:: 665:. 646:. 616:, 557:MR 555:, 543:11 541:, 537:, 505:MR 495:; 411:, 267:, 197:. 161:. 141:, 671:. 652:. 625:. 612:: 591:. 564:. 549:: 533:n 516:. 482:. 426:. 363:d 353:d 343:d 335:d 309:d 305:d 273:F 269:E 261:V 244:, 241:2 238:= 235:F 232:+ 229:E 223:V 115:. 95:. 55:. 34:. 20:)

Index

Side (plane geometry)
Edge (graph theory)
Three edges AB, BC, and CA, each between two vertices of a triangle.
vertices
triangle
A polygon is bounded by edges; this square has 4 edges.
square
Every edge is shared by two faces in a polyhedron, like this cube.
faces
polyhedron
cube
Every edge is shared by three or more faces in a 4-polytope, as seen in this projection of a tesseract.
4-polytope
tesseract
geometry
line segment
vertices
polygon
polyhedron
polytope
faces
diagonal
graph theory
edge
graph vertices
skeleton
Steinitz's theorem
3-vertex-connected
planar graphs
convex polyhedron

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