How many faces are there on an icosahedron?
Icosahedron congruent rhombs. It can be derived from the rhombic triacontahedron by removing 10 middle faces. Even though all the faces are congruent, the rhombic icosahedron is not face-transitive. Common icosahedra with pyramid and prism symmetries include: Several Johnson solids are icosahedra: Icosahedron In geometry, an icosahedron ( or ) is a polyhedron with 20 faces. The name comes . The plural can be either "icosahedra" () or "icosahedrons". There are many kinds of icosahedra, with some being more symmetrical than others. The best known is the Platonic, convex regular icosahedron. There are two objects, one convex and one nonconvex, that
Regular icosahedron the icosahedron itself. One is a regular Kepler–Poinsot polyhedron. Three are regular compound polyhedra. The small stellated dodecahedron, great dodecahedron, and great icosahedron are three facetings of the regular icosahedron. They share the same vertex arrangement. They all have 30 edges. The regular icosahedron and great dodecahedron share the same edge arrangement but differ in faces (triangles vs pentagons), as do the small stellated dodecahedron and great icosahedron (pentagrams vs triangles). There are distortions of the icosahedron that, while no longer regular, are nevertheless vertex-uniform. These are invariant under the same rotations as the tetrahedron, and are somewhat analogous to