Question

If the measure of 1 is x and the measure of <2 is x+50, what is the measure of <4?

A. 50
B. 55
C. 110
D. 115

Answer 1

Measure of angle 4 is 115°

Explanation:

First, we want to find the measure of angle 2, because the measure of angle 2 is equal to angle 4. When 2 straight lines cross each other, the angles formed are always equal to the angle right across from it.

Find angle 2 by setting up an equation:

`x+x+50=180`

This is basically saying that angle 1 plus angle 2 equals 180°. In a half turnaround, the angle is 180°. Angle 1 and 2 make up a half turnaround.

Solve the equation:

`x+x+50=180`

Combine the 2 x's to get 2x.

`2x+50=180`

Subtract 50 from both sides.

`2x=130`

Divide both sides by 2.

`x=65`

Since x=65, plug 65 into x in the measure of angle 2 (x+50).

65+50=115.

Since Angle 2 is equal to angle 4, angle 4 is also 115.