Use the relationship between supplementary angles ∠a and ∠b . What is m∠a if m∠b=121° ?(1 point)Responses301°301 degrees59°59 degrees31°31 degrees121°
If ∠a and ∠b are supplementary angles, it means that the sum of their measures is equal to 180 degrees.
Therefore, if m∠b = 121°, we can find m∠a by subtracting 121° from 180°:
m∠a = 180° - 121°
m∠a = 59°
So, the measure of ∠a is 59 degrees.