Answer:
m∠B = 54°
Step-by-step explanation:
Note: Complementary angles add up to 90°
Thus, m∠A and m∠B must add up to 90.
We can then write this equation.
x - 15 + x + 3 = 90
Simplify.
2x - 12 = 80
Add 12 to both sides.
2x = 102
x = 51
m∠B is (x + 3) , so m∠B = 51+ 3 = 54°
Just in case, let's double check. Plug 39 for x into m∠A to get
m∠A = 51 - 15 = 36
Then, plug the angle measures in.
36 + 54 = 90
90 = 90
Thus, the answer is correct.
I hope this helps! Feel free to ask any questions! :)
