# How do you find the missing side a given 12mm, 15mm right triangle using the Pythagorean Theorem?

Aug 11, 2018

The question doesn't state if you are looking for the hypotenuse or not.
If you are:
${a}^{2} + {b}^{2} = {c}^{2}$
${12}^{2} + {15}^{2} = {c}^{2}$
$c = \sqrt{369}$

If you already have the hypotenuse:
${c}^{2} - {b}^{2} = {a}^{2}$
${15}^{2} - {12}^{2} = {a}^{2}$
$a = \sqrt{84}$