Totally soundless proof that c=a+b, and not c=√(a²+b²) Say you draw a rectangle around a right triangle, and then remove the corner above the hypotenuse. The perimeter is still the same. If you remove the two new corners that were formed by the removal of the first corner, the perimeter is STILL the same. Repeat enough times and you'll eventually reach the hypotenuse. The perimeter is still the same. Using this method, the diagonal length seems to be the sum of a and b. Of course, this isn't true, but I'm too lazy to explain why so just look up the MSA page.
