Raymond B. answered 10/08/21
Math, microeconomics or criminal justice
The Pythagorean Theorem says
h^2 = a^2 + b^2
the hypotenuse squared = the sum of the squares of the two other sides of a right triangle, the altitude squared + base squared.
It's a special case of the Law of Cosines
c^2 = a^2 + b^2 -2abCosC where C= 90 degrees or pi/2,
c^2 = a^2 +b^2 -2ab(Cos90)
c^2 =a^2 + b^2 -2ab(0)
c^2 = a^2 +b^2
There are 100+ proofs of the Theorem. You can find them on line.
Mostly geometric in nature. Former US President James A. Garfield invented a novel proof when he was in the House of Representatives. His proof is published in math journals and can be found online.
The diagonal of a rectangle = d = the square root of the sum of the sides squared
d^2 = w^2 + l^2
d = square root of (w^2 + l^2) where w=width and l=length of the rectangle.