projections of point P onto lateral faces of pyramid are concyclic
Source: 2007 Oral Moscow Geometry Olympiad grades 10-11 p5
October 19, 2020
geometrypyramidConcyclic
Problem Statement
At the base of the quadrangular pyramid lies the quadrangle . whose diagonals are perpendicular and intersect at point , and is the altitude of the pyramid. Prove that the projections of the point onto the lateral faces of the pyramid lie on the same circle.(A. Zaslavsky)