IMO Shortlist 1990 problem 12
Kvaliteta:
Avg: 0,0Težina:
Avg: 0,0 Let be a triangle, and let the angle bisectors of its angles and meet the sides and at the points and , respectively. The lines and meet the line through the point parallel to at the points and respectively, and we have . Prove that .
Original formulation:
Let be a triangle and the line through parallel to the side Let the internal bisector of the angle at meet the side at and the line at and let the internal bisector of the angle at meet the side at and the line at If prove that
Original formulation:
Let be a triangle and the line through parallel to the side Let the internal bisector of the angle at meet the side at and the line at and let the internal bisector of the angle at meet the side at and the line at If prove that
Izvor: Međunarodna matematička olimpijada, shortlist 1990