Truncated Trigonal [s]Pyramid[/s] Trouble!
Source: XVII Sharygin Correspondence Round, P24
March 2, 2021
geometry3D geometrypyramid
Problem Statement
A truncated trigonal pyramid is circumscribed around a sphere touching its bases at points . Let be the altitude of the pyramid, be the circumradii of its bases, and be the circumcenters of the bases. Prove that