is listed below for each of the eight convex deltahedra. The deltahedra shouldn't be confused with the deltohedra (spelled with an "o"), polyhedra whose faces are geometric kites. The eight convex deltahedra There are only 8 strictly-convex deltahedra: Name Image Faces Edges Vertices Vertex configurations Symmetry group regular tetrahedron 4 6 4 4 × 33 T_d triangular dipyramid 6 9 5 2 × 333 × 34 D_ regular icosahedron 20 30 12 1… (More on Deltahedron)