Question

what is the measurement of this angle?

Explanation:

Step1: Determine the scale

There are two sets of scales on the protractor.

Step2: Read the angle

The outer - scale is used here. One side of the angle is at $120^{\circ}$ and the other is at $160^{\circ}$.

Step3: Calculate the angle

Subtract the smaller value from the larger value: $160 - 120=40$.

Answer:

$40^{\circ}$