Edges 15 Vertex configuration 2x3(3.5)
3(3.5) | Vertices 9 Symmetry group C3v | |
 | ||
Type Johnson
J62 - J63 - J64 Faces 2+3 triangles
3 pentagons | ||
In geometry, the tridiminished icosahedron is one of the Johnson solids (J63).
A Johnson solid is one of 92 strictly convex polyhedra that have regular faces but are not uniform (that is, they are not Platonic solids, Archimedean solids, prisms or antiprisms). They were named by Norman Johnson, who first listed these polyhedra in 1966.
The name refers to one way of constructing it, by removing three pentagonal pyramids from a regular icosahedron, which replaces three sets of five triangular faces from the icosahedron with three mutually adjacent pentagonal faces.
Related polytopes
The tridiminished icosahedron is the vertex figure of the snub 24-cell, a uniform 4-polytope (4-dimensional polytope).
References
Tridiminished icosahedron Wikipedia(Text) CC BY-SA