Triangular triswirlprism

The triangular triswirlprism is a convex isogonal polychoron and member of the duoprismatic swirlprism family that consists of 18 triangular antiprisms and 54 phyllic disphenoids. 4 antiprisms and 8 disphenoids join at each vertex. It can be obtained as a subsymmetrical faceting of the enneagonal duoprism. It is the third in an infinite family of isogonal triangular dihedral swirlchora.

The ratio between the longest and shortest edges is 1:$$\frac{\sqrt6}{4\sin\frac\pi9}$$ ≈ 1:1.79046.

Vertex coordinates
Coordinates for the vertices of a triangular triswirlprism constructed as the convex hull of three triangular duoprisms of edge length 1, are given as Cartesian products of the vertices of triangle T 1:
 * T 1 × T 1,
 * T 2 × T 2 (T 1 rotated 40 degrees),
 * T 3 × T 3 (T 1 rotated 80 degrees).