IMO 2009 Shortlist G1

Let ABC be a triangle with AB = AC. The angle bisectors of A and B meet the sides BC and AC in D and E, respectively. Le...

IMO 2009 Shortlist G1

Category: Geometry

Problem

Let ABC be a triangle with AB = AC. The angle bisectors of A and B meet the sides BC and AC in D and E, respectively. Let K be the incenter of triangle ADC. Suppose that ∠BEK = 45◦ . Find all possible values of ∠BAC.