Use the relationship between supplementary angles a and b. What is m a if m b = 121 degrees?

A. 59 degrees
B. 301 degrees
C. 31 degrees
D. 121 degrees

1 answer

A. 59 degrees

Since supplementary angles add up to 180 degrees, if angle b is 121 degrees, angle a would be:

m a = 180 - m b
m a = 180 - 121
m a = 59 degrees