Complementary angles are adjacent angles which add to equal 90 degrees (a right angle). To find m∠A in these figures, set the sum of the known angle measure and the unknown angle measure, A, equal to 90 and solve.
10)
90 = 67 + A
23 = A
m∠A = 23°
11)
90 = 57 + A
33 = A
m∠A = 33°
12)
90 = 44 + A
46 = A
m∠A = 46°