Question

find cos (a) given the triangle. enter your answer as a fraction. 231 a 108 255

Explanation:

Step1: Recall cosine definition

For acute angle $a$ in right triangle, $\cos(a) = \frac{\text{adjacent}}{\text{hypotenuse}}$

Step2: Identify side values

Adjacent to $a$: $231$, Hypotenuse: $255$

Step3: Simplify the fraction

$\cos(a) = \frac{231}{255} = \frac{77}{85}$

Answer:

$\frac{77}{85}$