MathDB
Geo with incircles

Source: Russian TST 2014, Day 7 P2 (Group NG), P3 (Groups A & B)

April 21, 2023
geometryincircle

Problem Statement

In an acute-angled triangle ABCABC, the point HH{} is the orthocenter, MM{} is the midpoint of the side BCBC and ω\omega is the circumcircle. The lines AH,BHAH, BH and CHCH{} intersect ω\omega a second time at points D,ED, E and FF{} respectively. The ray MHMH intersects ω\omega at point JJ{}. The points KK{} and LL{} are the centers of the inscribed circles of the triangles DEJDEJ and DFJDFJ respectively. Prove that KLBCKL\parallel BC.