2020 IMO Problems/Problem 1
. Consider the convex quadrilateral
. The point
is in the interior of
. The following ratio equalities hold:
Prove that the following three lines meet in a point: the internal bisectors of angles
and
and the perpendicular bisector of segment
.
Video solution
https://youtu.be/bDHtM1wijbY [Shorter solution, video covers all day 1 problems]