IMO Shortlist 2011 problem G7
Kvaliteta:
Avg: 0,0Težina:
Avg: 9,0 Let be a convex hexagon all of whose sides are tangent to a circle with centre . Suppose that the circumcircle of triangle is concentric with . Let be the foot of the perpendicular from to . Suppose that the perpendicular from to intersects the line at a point . Let be the foot of the perpendicular from to . Prove that .
Proposed by Japan
Proposed by Japan
Izvor: Međunarodna matematička olimpijada, shortlist 2011