△abc is a right triangle with right angle at ∠b .
ab=42 cm
bc=34 cm

what is the measure of ∠a , to the nearest degree?

We are tasked to solve for the ∠A in the given ΔABC where it is a triangle. Hence, we know that one angle is equivalent to 90°.

Other values given are the following:
AB = 42 cm
BC = 34 cm

Solving for ∠A is shown below:
sin A = opposite/hypotenuse
sin A = 34/42
A = 50.05°

The answer for ∠A is 50.05°.

This is the correct answer, I have taken the test and am posting the answers in hopes of helping other people :]

The answer is part a: use