| Enneagrammic crossed-antiprism | |
|---|---|
| Type | Uniform polyhedron |
| Faces | 2 Enneagrams 18 triangles |
| Edges | 36 |
| Vertices | 18 |
| Vertex configuration | 9/5.3.3.3 |
| Wythoff symbol | |2 2 9/5 |
| Symmetry group | D9d |
| Dual polyhedron | Enneagrammic concave deltohedron |
| Properties | nonconvex |
| Vertex figure | |
In geometry, the enneagrammic crossed-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.
It differs from the enneagrammic antiprism (9/4) by having opposite orientations on the two enneagrams.