MathDB
Two incentres collinear with two points of intersection

Source: Pan African MO 2006 Q6

May 1, 2013
symmetrygeometrygeometric transformationrotationAsymptotegeometry unsolved

Problem Statement

Let ABCABC be a right angled triangle at AA. Denote DD the foot of the altitude through AA and O1,O2O_1, O_2 the incentres of triangles ADBADB and ADCADC. The circle with centre AA and radius ADAD cuts ABAB in KK and ACAC in LL. Show that O1,O2,KO_1, O_2, K and LL are on a line.
Back to ProblemsView on AoPS