Trisnub icosahedron (near-miss)

This non-convex isogonal polyhedron is a faceting of a deformed compound of twelve pentagrammic retroprisms. This near-miss is notable for being topologically regular since all of its faces are triangles and 10 of them join at each vertex. It has 3 different edge lengths: 1, ~1.04054, ~1.06482.



Its dual is an isohedral decagrammic hexecontahedron.

(The dual is also topologically regular since all of its faces are decagrams and 3 of them join at each vertex).