Answer: 140
Step-by-step explanation:
Angles 3 and 4 have equivalent degree values. Set them equal to each other: x + 30 = 2x - 80
Solve for x: add 80 to both sides
x + 110 = 2x
Then subtract x from both sides
110 = x. This is x, not the final answer. The question asks for the measure of angle 3.
To get the measure of angle 3, plug in 110 for x.
Instead of x + 30, calculate 110 + 30.
So, angle 3 is 140 degrees.