Fig. 1053.37 Spherical Great Circles Are Commensurable with Spherical Triangles of Three Prime Structural Systems: Tetra Octa and Icosa:
A. Internal area of one great circle of a sphere
B. Surface triangle of spherical tetrahedron
C. Surface triangle of spherical octahedron
D. Surface triangle of spherical icosahedron
[1 great circle = 1 tetra triangle = 2 octa triangles = 5 icosa triangles = 30 basic LCD triangles]