Use the relationship between supplementary angles ∠a

Question

and ∠b
. What is m∠a if m∠b=121° ?(1 point)
Responses

121°
121 degrees

31°
31 degrees

59°
59 degrees

301°

Answer 1

The correct answer is 59°. Since ∠a and ∠b are supplementary angles, the sum of their measures is 180°. Therefore, if ∠b is 121°, then ∠a would be 180° - 121° = 59°.