GeometryDifficulty 3.0Prove itUKMT Senior Kangaroo · United Kingdom · 2018
A square ABCD has side 40 units. Point F is the midpoint of side AD. Point G lies on CF such that 3CG=2GF. What is the area of triangle BCG?
This one wants a proof. Work it on paper, then check yourself against the publisher's own solution, linked below. Be honest about it: the record is only any use to you if it is.