Icosahedron — De Divina Proportione

Twenty equilateral triangles — water in the Platonic elemental system, the most sphere-like of the five solids. Leonardo da Vinci for De Divina Proportione (1509). The most complex of the triangular solids: thirty edges, twelve vertices, twenty faces, all in the harmony of a figure that almost is a sphere. Catalog No. 4105.