Jonathan Mason - Variant Pythagoras

There are many geometric proofs of Pythagoras’s Theorem showing that, for a right angle triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. Here we have a geometric proof that, for a triangle where the critical angle is 120 degrees instead of 90, the square of the hypotenuse is equal to the sum of the squares of the other two sides plus their product. This is an original, or independently discovered, proof by Dr Jonathan Mason.

Jonathan is an academic-related member of the Administrative Support Team in the Mathematical Institute, University of Oxford.