Polyhedra and Polytopes This page includes pointers on geometric properties of polygons, polyhedra, and higher dimensional polytopes (particularly convex polytopes). Other pages of the junkyard collect related information on triangles, tetrahedra, and simplices cubes and hypercubes polyhedral models , and symmetry of regular polytopes - Adventures among the toroids
. Reference to a book on polyhedral tori by B. M. Stewart. Bob Allanson's Polyhedra Page . Nice animated-GIF line art of the Platonic solids, Archimedean solids, and Archimedean duals. Almost research-related maths pictures . A. Kepert approximates superellipsoids by polyhedra. Archimedean polyhedra , Miroslav Vicher. Archimedean solids: John Conway describes some interesting maps among the Archimedean polytopes . Eric Weisstein lists properties and pictures of the Archimedean solids Rolf Asmund's polyhedra page Associahedron and Permutahedron . The associahedron represents the set of triangulations of a hexagon, with edges representing flips; the permutahedron represents the set of permutations of four objects, with edges representing swaps. This strangely asymmetric view of the associahedron (as an animated gif) shows that it has some kind of geometric relation with the permutahedron: it can be formed by cutting the permutahedron on two planes. A more symmetric view is below. See also a more detailed description of the associahedron , and Jean-Louis Loday's paper on associahedron coordinates The bellows conjecture , R. Connelly, I. Sabitov and A. Walz in Contributions to Algebra and Geometry , volume 38 (1997), No.1, 1-10. Connelly had previously discovered non-convex polyhedra which are flexible (can move through a continuous family of shapes without bending or otherwise deforming any faces); these authors prove that in any such example, the volume remains constant throughout the flexing motion. | |
|