Feb 23, 2024
You can insert an icosahedron inside an octahedron.
If the edge length of the octahedron ist 1 + Phi (1.618), the egde length of the icosahedron is SQRT(2).
A friend showed me this picture by Casey house:
[Source: Caseys website ]
And I had to draw it in isometric projection.
Very neat.
One could also make that even further and put an octahedron into the icosahedron and so on...