Area of Spherical Triangle Small 320×292 Medium 640×583 Large 1024×934 Download TIFF Original 2400×2188 | (617.1 KB) Description Diagram used to prove the theorem: "The area of a spherical triangle, expressed in spherical degrees, is equal to its spherical excess expressed in angular degrees." Keywords area, degrees, spherical triangles Galleries Geometric Theorems and Proofs Source: Arthur Latham Baker The Elements of Solid Geometr with Numerous Exercises (Boston, MA: Ginn & Company, 1893)