Use the relationship between supplementary angles ∠a and ∠b . What is m∠a if m∠b=121° ?(1 point) Responses 59° 59 degrees 301° 301 degrees 31° 31 degrees 121°
Since supplementary angles add up to 180 degrees, if we know that one angle is 121 degrees, we can find the measure of the other angle by subtracting it from 180:
m∠a = 180 - m∠b = 180 - 121 = 59°
So, the measure of ∠a is 59 degrees.