KöMaL 2021 B5144

The area of a convex quadrilateral $ABCD$ is $t$ , and an interior point is $O$ . Show that $2t\le OA^2+OB^2+OC^2+OD^2.$ When will equality occur?

Official text KöMaL. Quoted with source.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.