WILL GIVE BRAINLIEST!
Find the measure of ∠a. (Let b = 66°, and let c = 172°.)
m∠a =
°

Answer: a = 122*
The three angles added together form a circle or 360*.
Set a + b + c = 360 and solve for a
a + 66 + 172 = 360
Subtract 238 from both sides to get a
a = 122*