Sum of Angles of Spherical Triangle

Theorem
The sum of the angles of a spherical triangle is between $\pi$ and $3 \pi$ radians.

Also see

 * : Chapter $5$: Eternal Triangles: Astronomy
 * : Chapter $5$: Eternal Triangles: Astronomy
 * : Chapter $5$: Eternal Triangles: Astronomy
 * : Chapter $5$: Eternal Triangles: Astronomy