in the figure below, <1 measures (3x+20) and <2 measures x. what is the measure of <4?

Answer:
D. 140
Step-by-step explanation:
∠ 1 + ∠ 2 = 180
So:
(3x + 20) + x = 180
4x + 20 = 180
4x = 180 - 20
4x = 160
x = 160 / 4
x = 40
∠ 1 = ∠ 4
∠ 2 = ∠ 3
If ∠ 1 is equal to ∠ 4, just plug in for x and solve.
3x + 20 = 3(40) + 20 = 120 + 20 = 140