A large colored wireframe model that shows a Triacontahedron that includes a dodecahedron and an icosahedron.
It can be used to calculate the volume or the triacontahedron.
Using as only information that the diagonal of a pentagon whose side is a has a diagonal of size φa you can prove that the volume of the triacontaheron is 5/2.b.b.b where b is the large diagonal of the rhombus (the blue segment).