Answer:
B. m1 = 120
Explanation:
Since there is a right angle at 3 and 4, you can conclude that both those angles are 90 degrees as well.
Additionally, using the straight line rule for angle 5, 180 - 150 = 30
Now to calculate angle 2, you take both angles 3 and 5 and subtract from 180:
180 - 90 - 30 = 60
Using the straight line rule again for angle 1, 180 - 60 = 120
You can conclude that m1 = 120 degrees