[Jonty30]

If they legitimately solved this puzzle on their own, I still view this as a pretty good feat.

[algore]

I agree.

It sounds like an independent proof

[scrabblehack]

They proved the Pythagorean Theorem using trigonometric methods.

Now it’s “cheating” to simply let a = c*cos(x) and
b = c*sin(x) and proving that a^2 + b^2 = c^2.
I’m a bit unclear at what point a trigonometric method isn’t cheating.

I think I recall seeing their proof and yes I was impressed but I’m not a theoretician.