MathDB
Lots of perpendiculars

Source: Baltic Way 2017 Problem 14

November 11, 2017
geometry

Problem Statement

Let PP be a point inside the acute angle BAC\angle BAC. Suppose that ABP=ACP=90\angle ABP = \angle ACP = 90^{\circ}. The points DD and EE are on the segments BABA and CACA, respectively, such that BD=BPBD = BP and CP=CECP = CE. The points FF and GG are on the segments ACAC and ABAB, respectively, such that DFDF is perpendicular to ABAB and EGEG is perpendicular to ACAC. Show that PF=PGPF = PG.