in geometry, the ditrigonal dodecadodecahedron (or ditrigonary dodecadodecahedron) is a nonconvex uniform polyhedron, indexed as u. it has extended schläfli symbol b{5,5/2}, as a "blended great dodecahedron", and coxeter diagram . it has 4 schwarz triangle equivalent constructions, for example wythoff symbol 3 | 5/3 5, and coxeter diagram .