Stellated Dodecahedron illustration. A regular dodecahedron or pentagonal dodecahedron is a dodecahedron that is regular, which is composed of 12 regular pentagonal faces, three meeting at each vertex. It is one of the five Platonic solids. A stellated dodecahedron extends each of the 12 pentagrams with 5 triangles that all come together at their apexes creating a 5-sided pyramid