Rabbit holes
Da Vinci
Divine proportion
Dodecahedron
Dymaxion
Euclid
Golden mean
Hexagon
Icosahedron
Icosidodecahedron
Making a lamp
Motivation
Octagon
Pentagon
Pacioli
Paper
Plato
Rhombicosido-
decahedron
Rhombicub-
octahedron
Symmetry
Truncation
Wood
Zometool
The icosahedron – 5
The icosidodecahedron
If you then draw a regular triangle inside of each hexagon of a truncated icosahedron, so that the tips of the triangles touch the middle of three of the edges of the hexagon, the outline that the edges of those triangles inscribe on the surface of the polyhedron is an icosidodecahedron.