Question 908865
Complementary angles add up to 90 degrees
A + B = 90
A = 2B+21
Substitute the value of A from the second equation into the first
A + B = 90
(2B+21) + B = 90
3B + 21 = 90
3B = 69
B = 23
If B is 23, then A is (2*23)+21, or 46+21, or 67