In geometry, an icosahedron ( /ˌaɪkɵsəˈhiːdrən/ or /aɪˌkɒsəˈhiːdrən/) is a regular polyhedron with 20 identical equilateral triangular faces, 30 edges and 12 vertices. It is one of the five Platonic solids.

It has five triangular faces meeting at each vertex. It can be represented by its vertex figure as or 35, and also by Schläfli symbol {3,5}. It is the dual of the dodecahedron, which is represented by {5,3}, having three pentagonal faces around each vertex.

The name comes from the Greek: εικοσάεδρον, from είκοσι (eíkosi) "twenty" and ἕδρα (hédra) "seat". The plural can be either "icosahedrons" or "icosahedra" (-/drə/).

Read more about Icosahedron:  Dimensions, Area and Volume, Cartesian Coordinates, Orthogonal Projections, Other Facts, Construction By A System of Equiangular Lines, Symmetry, Stellations, Geometric Relations, Uniform Colorings and Subsymmetries, Related Polyhedra and Polytopes, As A Graph