Difference between revisions of "2020 IMO Problems/Problem 1"

(Video solution)
(Video solution)
Line 7: Line 7:
  
 
https://youtu.be/rWoA3wnXyP8
 
https://youtu.be/rWoA3wnXyP8
 +
 
https://youtu.be/bDHtM1wijbY [Shorter solution, video covers all day 1 problems]
 
https://youtu.be/bDHtM1wijbY [Shorter solution, video covers all day 1 problems]

Revision as of 21:43, 3 October 2020

Problem 1. Consider the convex quadrilateral ABCD. The point P is in the interior of ABCD. The following ratio equalities hold: ∠P AD : ∠P BA : ∠DP A = 1 : 2 : 3 = ∠CBP : ∠BAP : ∠BP C. Prove that the following three lines meet in a point: the internal bisectors of angles ∠ADP and ∠P CB and the perpendicular bisector of segment AB.

Video solution

https://youtu.be/rWoA3wnXyP8

https://youtu.be/bDHtM1wijbY [Shorter solution, video covers all day 1 problems]

Invalid username
Login to AoPS