Question

What is the measure of ∠MIJ?

Answer 1

I believe you would need to subtract 55 from 180 (the measure of a straight line)
180 - 55 = 125
125 is your answer

You could also solve by process of elimination
A and B can't be the answer as they are less than a 90-degree angle, and MIJ is clearly an obtuse angle (an angle greater than 90-degrees)
D can't be the answer as the 305 is greater than a straight angle (180)
So C is the only logical answer

Answer 2

<MIJ = 1/2(360 - 2(55))
<MIJ = 1/2(360 - 110)
<MIJ = 1/2(250)
<MIJ = 125
answer is C. 125