in geometry, the truncated dodecadodecahedron (or stellatruncated dodecadodecahedron) is a nonconvex uniform polyhedron, indexed as u. it is given a schläfli symbol t{5/3,5}. it has 120 vertices and 54 faces: 30 squares, 12 decagons, and 12 decagrams. the central region of the polyhedron is connected to the exterior via 20 small triangular holes.