circumcenter() returns a 3-vector cartesian point, so i don't think D and delta will have the correct type here.

that was a typo, sorry. should have been circumcircle()

if you want you can also change xyz and go functions to convert degrees <-> radians

I also fixed it so it considers the triangle to be smaller than a hemisphere irrespective of orientation (previously it was always considering spherical triangles to be oriented the same way.