Question

find: cos b
answer
the figure is not drawn to scale*

Explanation:

Step1: Recall the cosine formula

In a right - triangle, $\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}$. For angle $B$, the adjacent side is $68$ and the hypotenuse is $85$.

Step2: Calculate $\cos B$

$\cos B=\frac{68}{85}$. Simplify the fraction: $\frac{68\div17}{85\div17}=\frac{4}{5}$ (but in the given options, we just present the fraction as is from the formula application).

Answer:

$\frac{68}{85}$