MathDB
MMO 003 Moscow MO 1935 angles in a pyramid

Source:

July 17, 2019
pyramidgeometry3D geometryangles

Problem Statement

The base of a pyramid is an isosceles triangle with the vertex angle α\alpha. The pyramid’s lateral edges are at angle ϕ\phi to the base. Find the dihedral angle θ\theta at the edge connecting the pyramid’s vertex to that of angle α\alpha.