Spherical law of cosines
= Spherical law of cosines
{wiki=Spherical_law_of_cosines}
The Spherical Law of Cosines is a fundamental theorem in spherical geometry, which deals with the relationships between the angles and sides of spherical triangles (triangles drawn on the surface of a sphere). Specifically, it is used to relate the lengths of the sides of a spherical triangle and the cosine of one of its angles.