Question

find the measure of angle y in degrees. round to two decimal places as necessary.
draw
(right triangle with one leg 8, hypotenuse 20, angle y at the bottom left vertex)

Explanation:

Step1: Identify adjacent/hypotenuse

For angle $y$, adjacent side = 8, hypotenuse = 20.

Step2: Use cosine definition

$\cos(y) = \frac{\text{adjacent}}{\text{hypotenuse}} = \frac{8}{20} = 0.4$

Step3: Solve for $y$ with arccos

$y = \arccos(0.4)$
Calculate using a calculator in degree mode:
$y \approx 66.4218^\circ$

Step4: Round to 2 decimals

Round $66.4218^\circ$ to two decimal places.

Answer:

$66.42^\circ$