Answer: 110˚
Explanation:
Complementary angles have a sum of 90˚
With this knowledge, we can say <B = 90 - <A = 90 - 20 = 70˚
Supplementary angles have a sum of 180˚
With this knowledge we can say <C = 180 - <B = 180 - 70 = 110˚
∴ Measure of angle C = 110˚