Fig. 3. "Elevated icosidodecahedron" from the manuscript version of De divina proportione. It is a nonconvex construction of 120 equilateral triangles arranged with icosahedral symmetry. Three-sided and five-sided pyramids have been erected on the faces of the underlying icosidodecahedron, which consists of twenty triangles and twelve pentagons. | top of page | return to text | |