spherical triangle

A spherical triangle is a triangle drawn on the surface of a sphere, rather than on a flat plane. Unlike traditional triangles, which have three straight sides, the sides of a spherical triangle are arcs of great circles (the largest circles that can be drawn on the sphere). Spherical triangles are often used in navigation and astronomy, as they allow for calculations involving angles and distances on the curved surface of the Earth. The sum of a spherical triangle's angles is always greater than 180 degrees and can be up to 540 degrees.