Pythagorean theorem is A squared + B squared = C squared. its used for right triangles IIRC
example: a right triangle with 3 sides, one side is 3″, one is 4″ and the longest is 5″.
3*3 + 4*4 = 5*5
9+16=25
25=25
(i took geometry a long time ago. this correct? LOL)