olymmath

RU-TST 2014

Russian IMO Team Selection Test 2014.

Other problems

Problem 2

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 KL∥BCKL\parallel BC .