TYB
assuming earth is a sphere,
-
find angular distances b/w the three (d/R), with R=earth radius, d=distance
-
use https://www.wolframalpha.com/input/?i=spherical+law+of+cosines to compute angles
TYB
assuming earth is a sphere,
find angular distances b/w the three (d/R), with R=earth radius, d=distance
use https://www.wolframalpha.com/input/?i=spherical+law+of+cosines to compute angles