Trigonometry Examples

 $\begin{matrix} Side & Angle \\ \begin{matrix} b = \\ c = \\ a = & 2 \end{matrix} & \begin{matrix} A = & 90 \\ B = & 2 \\ C = \end{matrix} \end{matrix}$

Step 1

The cosine of an angle is equal to the ratio of the adjacent side to the hypotenuse.

$\cos (B) = \frac{adj}{hyp}$

Step 2

Substitute the name of each side into the definition of the cosine function.

$\cos (B) = \frac{c}{a}$

Step 3

Set up the equation to solve for the adjacent side, in this case $c$ .

$c = a \cdot \cos (B)$

Step 4

Substitute the values of each variable into the formula for cosine.

$c = 2 \cdot \cos (2)$

Step 5

Multiply $2$ by $0.99939082$ .

$c = 1.99878165$