MathDB
Moldova TST triangle geometry

Source: Moldova TST 2014, First Day, Problem 3

March 4, 2014
geometrytrigonometrypower of a pointradical axisgeometry proposed

Problem Statement

Let ABC\triangle ABC be an acute triangle and ADAD the bisector of the angle BAC\angle BAC with D(BC)D\in(BC). Let EE and FF denote feet of perpendiculars from DD to ABAB and ACAC respectively. If BFCE=KBF\cap CE=K and AKEBF=L\odot AKE\cap BF=L prove that DLBFDL\perp BF.