Let ABC be a triangle with incentre I and circumcircle ω. The incircle of the triangle ABC
touches the sides BC, CA and AB at D, E and F, respectively. The circumcircle of triangle ADI crosses ω again at P, and the lines PE and PF cross ω again at Xand Y, respectively. Prove that the lines AI, BX and CY are concurrent. trigonometryAngle ChasingconcurrencygeometryRMM Shortlistcircumcircle