Question

Pythagorean Theorem help!

I just need a break-down of what it is~
I will give medals!

Answer 1

For any right angled triangle, the sum of the squares of the lengths of the opposite and adjacent sides equals the square of the length of the hypotenuse.

Answer 2

Or, given a right triange (which has one 90 degree angle), the length of the longest side is equal to the square root of the sum of the squares of the shorter sides.