I don’t understand how to do this

Answer:
Your answer is D, 139°. This is because it is equivalent to the other 139° angle that is also on line m
Answer:
your correct answer is D. 139 degrees
Step-by-step explanation:I would say, if you were homeschooled, you would be able to get all a's because after you submit assignments, you can see the answers, write them down, and re do the test and get 100% on everything! That is how I am!