Enneagrammic antiprism (9/4)

Enneagrammic antiprism (9/4)
Type Uniform polyhedron
Faces 2 Enneagrams
16 triangles
Edges 36
Vertices 18
Vertex configuration 9/4.3.3.3
Wythoff symbol |2 2 9/4
Symmetry group D9h
Dual polyhedron Enneagrammic deltohedron
Properties nonconvex
Vertex figure

In geometry, the {9/4} 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 {9/4} enneagrams.