Use the relationship between supplementary angles ∠a and ∠b . What is m∠a if m∠b=121°?(1 point) Responses 31° 31 degrees 301° 301 degrees 121° 121 degrees 59° 59 degrees
The relationship between supplementary angles is that they add up to 180 degrees. Therefore, if m∠b = 121°, then m∠a = 180° - m∠b.
m∠a = 180° - 121° = 59°.
Therefore, m∠a = 59°.