Enneagrammic antiprism (9/2)

Enneagrammic antiprism (9/2)
Type Uniform polyhedron
Faces 2 Enneagrams
18 triangles
Edges 36
Vertices 18
Vertex configuration 9/2.3.3.3
Wythoff symbol |2 2 9/2
Symmetry group D9h
Dual polyhedron Enneagrammic deltohedron
Properties nonconvex
Vertex figure

In geometry, the {9/2} enneagrammic antiprism is one in an infinite set of nonconvex antiprisms formed by triangle sides and two regular star polygon caps, in this case two {9/2} enneagrams.