MathDB
polyhedron has exactly 6 right dihedral angles.

Source: II Soros Olympiad 1995-96 R2 11.5 https://artofproblemsolving.com/community/c2416727_soros_olympiad_in_mathematics

June 3, 2024
geometry3D geometryanglespolyhedron

Problem Statement

66 points are taken on the surface of the sphere, forming three pairs of diametrically opposite points on the sphere. Consider a convex polyhedron with vertices at these points. Prove that if this polyhedron has one right dihedral angle, then it has exactly 66 right dihedral angles.