球きゅう面めん三さん角かく法ほう

noun

spherical trigonometry

A branch of mathematics dealing with triangles on the surface of a sphere, used in astronomy, geodesy, and navigation.

• 球きゅう面めん三さん角かく法ほうは、天てん文もん学がくや測そく地ち学がくで重じゅう要ような役やく割わりを果はたす。

  Spherical trigonometry plays an important role in astronomy and geodesy.