# How do you find the unknown angle if the adjacent of the triangle is 9 cm , the hypotenuse is 14 cm and the opposite side is unknown?

$\theta = {49.99}^{o}$

#### Explanation:

$14 \times \cos \left(\theta\right) = 9$

$\cos \left(\theta\right) = \frac{9}{14}$

$\theta = {\cos}^{-} 1 \left(\frac{9}{14}\right) = {49.99}^{o}$

The other side of the triangle is:

$x = \sqrt{{14}^{2} - {9}^{2}} = 10.72 c m$

The opposite angle is:

$\alpha = 180 - 90 - 49.99 = {40.01}^{o}$