Answer: 142°15'
Explanation:
Supplementary angles are angles that add up to make a straight angle ().
Therefore, we must find the angle ∠B such that
∠A + ∠B = 180° (1)
We know that ∠A = 37°45', so we can re-arrange equation (1) to find the magnitude of ∠B:
∠B = 180° - ∠A = 180° - 37°45' = 142°15'
So, the correct answer is
142°15'