Regular dodecahedron a dodecahedron. Regular dodecahedron A regular dodecahedron or pentagonal dodecahedron is a dodecahedron that is regular, which is composed of twelve regular pentagonal faces, three meeting at each vertex. It is one of the five Platonic solids. It has 12 faces, 20 vertices, 30 edges, and 160 diagonals (60 face diagonals, 100 space diagonals). It is represented by the Schläfli symbol {5,3}. If the edge length of a regular dodecahedron is "a", the radius of a circumscribed sphere (one that touches the regular dodecahedron at all vertices) is and the radius of an inscribed sphere (tangent to each of the
Truncated dodecahedron straight edges. It shares its vertex arrangement with three nonconvex uniform polyhedra: It is part of a truncation process between a dodecahedron and icosahedron: This polyhedron is topologically related as a part of sequence of uniform truncated polyhedra with vertex configurations (3.2"n".2"n"), and ["n",3] Coxeter group symmetry. In the mathematical field of graph theory, a truncated dodecahedral graph is the graph of vertices and edges of the "truncated dodecahedron", one of the Archimedean solids. It has 60 vertices and 90 edges, and is a cubic Archimedean graph. Truncated dodecahedron In geometry, the truncated dodecahedron is an Archimedean solid. It has