:O
I thought it was A squared plus B squared equals C squared, but it wouldn't matter as long as you don't mind negative numbers. I don't mind them. :P
Thats the formula when the hypotenuse is not known.
a² + b² = c² -> C = Hypotenuse variable - Used when the hypotenuse is unknown.
a² - c² = b² -> C = Unknown variable - Used when the hypotenuse is known.