Question

If angle A has a measurement of 42° and is complementary to angle B, what's the measure of angle B?

the correct answer is 48°

Answer 1

We know, the sum of complementary angles are 90
So, A + B = 90
42 + B = 90
B = 90 - 42
B = 48

In short, Your Answer would be 48

Hope this helps!