edge of polyhedron
21Tetrahedron — For the academic journal, see Tetrahedron (journal). Regular Tetrahedron (Click here for rotating model) Type Platonic solid Elements F = 4, E = 6 V = 4 (χ = 2) Faces by s …
22Octahedron — For the album by The Mars Volta, see Octahedron (album). Regular Octahedron (Click here for rotating model) Type Platonic solid Elements F = 8, E = 12 V = 6 (χ = 2) Faces by sides …
23Regular polytope — In mathematics, a regular polytope is a polytope whose symmetry is transitive on its flags, thus giving it the highest degree of symmetry. All its elements or j faces (for all 0≤ j ≤ n , where n is the dimension of the polytope) cells, faces and… …
24Crystal structure of boron-rich metal borides — Two single crystals of YB66 (1 cm diameter) grown by floating zone technique using (100) oriented seeds. In the top crystal, the seed (left from the black line) has same diameter as the crystal. In the bottom crystal (sliced), the seed is much… …
25Dodecahedron — Regular Dodecahedron (Click here for rotating model) Type Platonic solid Elements F = 12, E = 30 V = 20 (χ = 2) Faces by sides 12{5} …
26Cube — This article is about the geometric shape. For other uses, see Cube (disambiguation). Regular Hexahedron (Click here for rotating model) Type Platonic solid Elements F = 6, E = 12 V = 8 (χ = 2) …
27Planar graph — Example graphs Planar Nonplanar Butterfly graph K5 The complete graph K4 …
28Duality (mathematics) — In mathematics, a duality, generally speaking, translates concepts, theorems or mathematical structures into other concepts, theorems or structures, in a one to one fashion, often (but not always) by means of an involution operation: if the dual… …
29Midsphere — A polyhedron and its midsphere. The red circles are the boundaries of spherical caps within which the surface of the sphere can be seen from each vertex. In geometry, the midsphere or intersphere of a polyhedron is a sphere which is tangent to… …
30Cuboctahedron — (Click here for rotating model) Type Archimedean solid Uniform polyhedron Elements F = 14, E = 24, V = 12 (χ = 2) Faces by sides 8{3}+6{4} …
