Answer:
55
Explanation:
There are many ways to solve this problem; however, I used the one I believe to be the fastest and easiest, but you can still use a different way.
I solved this by using the fact that the green angle (m<125) and the red angle (x) make a straight line. All straight lines equal 180 degrees; therefore, this line must equal 125+x=180. Then, you can subtract 125 from both sides of the equation. That leaves x=55.