Question

In the diagram, the measure of angle 3 is (23x)°, and the measure of angle 4 is (7x)°.

What is the measure of angle 4?

A.30*
B.42*
C.120*
D.138*

Answer 1

B: 42°

Explanation:

Please comment if you need and explanation =)

Answer 2

Angles three and four are a linear pair, meaning that they they form a line. When two angles make a line, the measures add up to 180°. Adding the two values together, we see that 3x+27x=180. Simplifying and solving for x, we get 30x=180 ⇒ x=6.

The question, however, is asking for the measure of angle 4. Thus, we plug x=6 into 7x to get 6(7)=42.

Hope this helped!