15-2 step prism

The 15-2 step prism is a convex isogonal polychoron and a member of the step prism family. It has 90 phyllic disphenoids of six kinds as cells, with 24 joining at each vertex. It can also be constructed as the 15-7 step prism.

Using the ratio method, the lowest possible ratio between the longest and shortest edges is 1:$$\frac{\sqrt{51\sqrt5+\sqrt{23550-10470\sqrt5}-101}}{2}$$ ≈ 1:2.49010.

Vertex coordinates
Coordinates for the vertices of a 15-2 step prism inscribed in a pentadecagonal duoprism with base lengths a and b are given by: where k is an integer from 0 to 14. If the edge length differences are to be minimized, the ratio of a:b must be equivalent to 1:$$\frac{\sqrt{7+3\sqrt5+\sqrt{150+66\sqrt5}}}{2}$$ ≈ 1:2.78203.
 * (a*sin(2πk/15), a*cos(2πk/15), b*sin(4πk/15), b*cos(4πk/15)),