17-2 step prism

The 17-2 step prism is a convex isogonal polychoron and a member of the step prism family. It has 119 phyllic disphenoids of seven kinds as cells, with 28 joining at each vertex. It can also be constructed as the 17-8 step prism.

Vertex coordinates
Coordinates for the vertices of a 17-2 step prism inscribed in a heptadecagonal duoprism with base lengths a and b are given by: where k is an integer from 0 to 16. If the edge length differences are to be minimized, the ratio of a:b must be equivalent to 1:$$\frac{1}{\sqrt{2\cos\frac{\pi}{17}-2\cos\frac{2\pi}{17}}}$$ ≈ 1:3.14656.
 * (a*sin(2πk/17), a*cos(2πk/17), b*sin(4πk/17), b*cos(4πk/17)),