Answer:
56 Deg.
Step-by-step explanation:
First, you need to use the Exterior Angles Theorem which states that the two opposite sides of a exterior angle add up to the exterior angle. So in this case,
83 + m<1 = 139
So then, you can do algebra and subtract 83 from both sides.
Then,
m<1 = 139 - 83
m<1 = 56 Degrees.
