MathDB

2

Part of 2007 Czech and Slovak Olympiad III A

Problems(1)

prove a triangle is isoceles

Source: Czech and Slovak third round,2007,p2

3/3/2012
In a cyclic quadrilateral ABCDABCD, let LL and MM be the incenters of ABCABC and BCDBCD respectively. Let RR be a point on the plane such that LR⊥ACLR\bot AC and MR⊥BDMR\bot BD.Prove that triangle LMRLMR is isosceles.
geometryincentercyclic quadrilateralgeometry proposed