IMO 2003 - Problem 4: Easier Geometry for the IMO

TIMESTAMPS: 00:00 30 - 45/90 - 180 Take 20 minutes 00:40 Drawing the diagram 01:30 Solving the problem backwards (only if) 02:26 Trying to infer something from the angle bisectors 04:55 Restating the problem with our finding 05:24 Looking at the problem forwards 06:00 Angle chasing 07:18 Looking at the problem with the new fact and angle chasing 09:50 Another shot at PQ=QR via angle chasing 11:50 Trigonometric approach 15:08 Solving it with menelaus and similarity 18:45 Reflecting on the problem 21:27 Thanks for problem solving :)