MathDB
Collinearity [Switzerland 2011]

Source:

January 31, 2011
geometrycircumcirclegeometry proposed

Problem Statement

Let ABC\triangle{ABC} a triangle with CAB=90\angle{CAB}=90^{\circ} and LL a point on the segment BCBC. The circumcircle of triangle ABL\triangle{ABL} intersects ACAC at MM and the circumcircle of triangle CAL\triangle{CAL} intersects ABAB at NN. Show that LL, MM and NN are collinear.