Small ditrigonal icosidodecahedron

Small ditrigonal icosidodecahedron Type Uniform star polyhedron
Elements F = 32, E = 60
V = 20 (χ = −8)
Faces by sides 20{3}+12{5/2}
Wythoff symbol 3 | 5/2 3
Symmetry group Ih, [5,3], *532
Index references U30, C39, W70
Dual polyhedron Small triambic icosahedron
Vertex figure (3.5/2)3
Bowers acronym Sidtid

In geometry, the small ditrigonal icosidodecahedron (or small ditrigonary icosidodecahedron) is a nonconvex uniform polyhedron, indexed as U30. It has extended Schläfli symbol a{5,3}, as an altered dodecahedron, and Coxeter diagram     or    .

It is constructed from Schwarz triangle (3 3 5/2) with Wythoff symbol 3 | 5/2 3. Its hexagonal vertex figure alternates equilateral triangle and pentagram faces.

Related polyhedra

Its convex hull is a regular dodecahedron. It additionally shares its edge arrangement with the great ditrigonal icosidodecahedron (having the triangular faces in common), the ditrigonal dodecadodecahedron (having the pentagrammic faces in common), and the regular compound of five cubes. As a simple polyhedron it is also a hexakis truncated icosahedron where the triangles touching the pentagons are made coplanar, making the others concave.

a{5,3} a{5/2,3} b{5,5/2}
=            =

Small ditrigonal icosidodecahedron

Great ditrigonal icosidodecahedron