IMO Shortlist 2015 problem G2
Kvaliteta:
Avg: 0,0Težina:
Avg: 6,0Triangle has circumcircle and circumcenter . A circle with center intersects the segment at points and , such that , , , and are all different and lie on line in this order. Let and be the points of intersection of and , such that , , , , and lie on in this order. Let be the second point of intersection of the circumcircle of triangle and the segment . Let be the second point of intersection of the circumcircle of triangle and the segment .
Suppose that the lines and are different and intersect at the point . Prove that lies on the line .
(Greece)
Izvor: https://www.imo-official.org/problems/IMO2015SL.pdf