Mid-point Area

'Mid-point Area' printed from https://nrich.maths.org/

Rectangle with triangle PMR
$M$ is the midpoint of the side of the rectangle. What is the area (in square units) of the triangle $PMR$?

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.

This problem is taken from the UKMT Mathematical Challenges.

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