the film forum library tutorial contact |
The Octahedronfrom Curious and Interesting Geometry by David Wells |
If the edges of a regular octahedron are divided in the golden section so that the points of division for any face of the octahedron form an equilateral triangle, then the 12 points of division are the vertices of a regular icosahedron.
There are two ways in which the edges can be divided internally in the golden ratio, and two more ways in which they can be divided externally, producing a total of four icosahedrons. For external division, the points of division of the edges of one face are next-but-one vertices of the icosahedron.
learn more on topics covered in the film
see the video
read the script
learn the songs
discussion forum