MathDB
BP bisects segment DE, projections related (Kharkiv City XI 2019 Ukr)

Source:

March 22, 2020
geometryprojectionsbisects segmentKharkivaltitudes

Problem Statement

In the acute-angled triangle ABCABC, let CD,AECD, AE be the altitudes. Points FF and GG are the projections of AA and CC on the line DEDE, respectively, HH and KK are the projections of DD and EE on the line ACAC, respectively. The lines HFHF and KGKG intersect at point PP. Prove that line BPBP bisects the segment DEDE.