Great stellated dodecahedron of uniform polyhedra. Truncating edges down to points produces the great icosidodecahedron as a rectified great stellated dodecahedron. The process completes as a birectification, reducing the original faces down to points, and producing the great icosahedron. The truncated "great stellated dodecahedron" is a degenerate polyhedron, with 20 triangular faces from the truncated vertices, and 12 (hidden) pentagonal faces as truncations of the original pentagram faces, the latter forming a great dodecahedron inscribed within and sharing the edges of the icosahedron. Great stellated dodecahedron In geometry, the great stellated dodecahedron is a Kepler-Poinsot polyhedron, with Schläfli symbol {5/2,3}. It is one
Great dodecahedron pentagram, its two-dimensional analogue, via the extension of the ("n-1")-D pentagonal polytope faces of the core "n"D polytope (pentagons for the great dodecahedron, and line segments for the pentagram) until the figure again closes. It shares the same edge arrangement as the convex regular icosahedron; the compound with both is the small complex icosidodecahedron. If only the visible surface is considered, it has the same topology as a triakis icosahedron with concave pyramids rather than convex ones. The excavated dodecahedron can be seen as the same process applied to a regular dodecahedron. A truncation process applied to the great dodecahedron