# How do you find the missing angles when the sides of a right triangle are given?

In Triangle $A B C$ with the right angle at $C$, let $a$, $b$, and $c$ be the opposite, the adjacent, and the hypotenuse of $\angle A$. Then, we have
$\sin A = \frac{a}{c} R i g h t a r r o w \text{m} \angle A = {\sin}^{- 1} \left(\frac{a}{c}\right)$
$\sin B = \frac{b}{c} R i g h t a r r o w \text{m} \angle B = {\sin}^{- 1} \left(\frac{b}{c}\right)$