MathDB
Considering the planes of the frustum ABCDEF

Source: Romanian MO 2002

December 8, 2010
geometry3D geometryfrustumgeometry proposed

Problem Statement

Let [ABCDEF][ABCDEF] be a frustum of a regular pyramid. Let GG and GG' be the centroids of bases ABCABC and DEFDEF respectively. It is known that AB=36,DE=12AB=36,DE=12 and GG=35GG'=35. a)a) Prove that the planes (ABF),(BCD),(CAE)(ABF),(BCD),(CAE) have a common point PP, and the planes (DEC),(EFA),(FDB)(DEC),(EFA),(FDB) have a common point PP', both situated on GGGG'. b)b) Find the length of the segment [PP][PP'].