11. The product of two versors can be compared to a spherical triangle where two sides add to the third. 12. The resulting tesselation has 4 ?6 = 24 spherical triangles ( it is the spherical disdyakis cube ). 13. This is also the only uniform polyhedron that cannot be made by the Wythoff construction from a spherical triangle . 14. The solution of the celestial triangle used the John Napier rules for solution of square-angled spherical triangles . 15. The plane-triangle congruence theorem angle-angle-side ( AAS ) does not hold for spherical triangles . 16. Consider a spherical triangle one of whose vertices is the North Pole and the other two lie on the equator. 17. The general spherical triangle is fully determined by three of its six characteristics ( 3 sides and 3 angles ). 18. A spherical triangle is thus formed by the junction lines, the curves upon which average somewhere about sixty chains radius. 19. If the angles of the spherical triangle are chosen appropriately, the triangles will tile the sphere, one or more times. 20. Note that the sides of a spherical triangle are measured by angular rather than linear units, based on the corresponding central angles.
