MEMO 2016 ekipno problem 5
Kvaliteta:
Avg: 0,0Težina:
Avg: 6,0Let be an acute-angled triangle with , and let be its circumcentre. The line intersects the circumcircle of a second time in point , and the line in point . The circumcircle of intersects the line a second time in point . The line intersects the line in point . The line through parallel to intersects the altitude of the triangle that passes through in point .
Prove that .
Izvor: Srednjoeuropska matematička olimpijada 2016, ekipno natjecanje, problem 5