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
Rhombicuboctahedron 2
It's all a matter of perspective
In this closeup, from which I have removed the background, you can see the details of Leondardo's carefully painted shadings.