R/r of set of tetrahedra with concentric inscribed + circumscribed spheres
Source: Austrian - Polish 1986
May 16, 2019
geometrytetrahedronsphereconcentricinscribedcircumscribed3D geometry
Problem Statement
Let be the set of all tetrahedra whose inscribed and circumscribed spheres are concentric. If the radii of these spheres are denoted by and respectively, find the possible values of over all tetrahedra from .