
I made this using Stella 4d: Polyhedron Navigator. You can try this program for free at http://www.software3d.com/Stella.php.

I made this using Stella 4d: Polyhedron Navigator. You can try this program for free at http://www.software3d.com/Stella.php.



To make this polyhedron, I first changed the symmetry-type of a dodecahedron from icosahedral to tetrahedral, then stellated it twice. This was done using Stella 4d, a program you may try for free at http://www.software3d.com/Stella.php.

This expanded version of the rhombicosidodecahedron has, as faces, 30 rhombi, 60 almost-square trapezoids, twelve regular pentagons, and twenty equilateral triangles, for a total of 122 faces. I made it using Stella 4d, software you may try for free at http://www.software3d.com/Stella.php.
I call this an “expansion of the rhombicosidodecahedron” because it is similar in appearance to that Archimedean solid. However, it is formed by augmenting the thirty faces of a rhombic triacontahedron with prisms, making the convex hull of the result, and then using Stella‘s “try to make faces regular” function on that convex hull.