M2 = 50°, m 3 = 100°, m 4 = 30 50 100 150

150 D

Explanation:

In a triangle the interior angles must add up to 180, so to find angle 1 you must subtract angles 2 and 3 from 180:

180-100 = 80

80-50 = 30

So the measure of angle 1 is 30. Now because we know that a straight line is 180 degrees, we know that if there is a line connected to it, the angles that it forms must add back up to 180. So we would subtract angle 1 from 180 to get angle 4:

180-30 = 150

That is why 150 or D is your answer.

Hope this helps!