Question

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

Answer 1

D. 140

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