Given an isosceles triangle ABC such that ∣AB∣=∣AC∣ . Let M be the midpoint of the segment BC and let P be a point other than A such that PA∥BC. The points X and Y are located respectively on rays PB and PC, so that the point B is between P and X, the point C is between P and Y and ∠PXM=∠PYM. Prove that the points A,P,X and Y are concyclic. geometryConcyclicisoscelesequal angles