Difference between revisions of "2022 IMO Problems/Problem 4"

Line 8: Line 8:
  
 
==Solution==
 
==Solution==
https://www.youtube.com/watch?v=-AII0ldyDww [Video contains solutions to all day 1 problems]
+
https://www.youtube.com/watch?v=-AII0ldyDww [Video contains solutions to all day 2 problems]

Revision as of 05:47, 23 July 2022

Problem

Let $ABCDE$ be a convex pentagon such that $BC = DE$. Assume that there is a point $T$ inside $ABCDE$ with $TB = TD$, $TC = TE$ and $\angle ABT = \angle TEA$. Let line $AB$ intersect lines $CD$ and $CT$ at points $P$ and $Q$, respectively. Assume that the points $P, B, A, Q$ occur on their line in that order. Let line $AE$ intersect lines $CD$ and $DT$ at points $R$ and $S$, respectively. Assume that the points $R, E, A, S$ occur on their line in that order. Prove that the points $P, S, Q, R$ lie on a circle.

Solution

https://www.youtube.com/watch?v=-AII0ldyDww [Video contains solutions to all day 2 problems]