Enneagrammic prism

9-2 enneagrammic prism
Type	Uniform polyhedron
Faces	2 enneagrams 9 squares
Edges	27
Vertices	18
Vertex configuration	9/2.4.4
Wythoff symbol	2 9/2 | 2
Symmetry group	D9h, [2,9],(*299), order 36
Dual polyhedron	Enneagrammic bipyramid
Properties	nonconvex
Vertex figure

9-4 enneagrammic prism Type Uniform polyhedron Faces 2 enneagrams 9 squares Edges 27 Vertices 18 Vertex configuration 9/4.4.4 Wythoff symbol 2 9/4 | 2 Symmetry group D9h, [2,9],(*299), order 36 Dual polyhedron Enneagrammic bipyramid Properties nonconvex Vertex figure

In geometry, the enneagrammic prism is a nonconvex prisms formed by squares sides and two regular star polygon caps. There are two forms based on the two types of enneagrams: {9/2} and {9/4}.

Sources

• Antiduoprisms at polytope.net
• A128112 at oeis.org