What is one method to find the measure of angle B?

Answer:
A.
Step-by-step explanation:
Since we have two sides, we can use the Pythagorean Theorem to find the other side, and use any trig function to find B. For the option B, Nowhere in the problem does it state an angle except the 90 degree angle. So we can't find an angle without trig functions. For option C, it wants to trick you. The formula for cosine is adj/hyp, not opp/hyp. The opp of B is 8, and the hyp is root 89. So that function is actually sine, not cosine.