It was just a joke... exhaustive search would mean checking that the statement holds true for every possible right angled triangle.
I rather quite like Euclid's construction of this proof, but don't just want to copy.
Might think about it a while and try put together a real proof that doesn't involve checking an infinite number of triangles...
I took it literally and thought you searched the web for a solution for hours and are exhausted by now, xD.
It is quite tough to come up with an original proof when you already know one, but I would appreciate it.
I heard it is still a lively competition to try and come up with new ways of proving Pythagoras