MathDB
Show that three lines are concurrent

Source: Turkey Junior National Olympiad 2013 P3

November 29, 2013
geometrycircumcirclegeometry proposed

Problem Statement

Let ABCABC be a triangle such that AC>AB.AC>AB. A circle tangent to the sides ABAB and ACAC at DD and EE respectively, intersects the circumcircle of ABCABC at KK and LL. Let XX and YY be points on the sides ABAB and ACAC respectively, satisfying \frac{AX}{AB}=\frac{CE}{BD+CE}   \text{and}   \frac{AY}{AC}=\frac{BD}{BD+CE} Show that the lines XY,BCXY, BC and KLKL are concurrent.