Fig. 458.12 Folding of Great Circles into the Icosahedron
System:
 The 15 great circles of the icosahedron folded into
"multibowties" consisting of four tetrahedrons
each. Four times 15 equals 60, which is 1/2 the number
of triangles on the sphere. Sixty
additional triangles inadvertently appear, revealing
the 120 identical (although right and left
handed) spherical triangles, which are the maximum number
of like units that may be used to
subdivide the sphere.
 The six greatcircle icosahedron system created from
six pentagonal "bowties."
