Question

Which of the following could be the measure of the angle below?

On a coordinate plane, a horizontal straight line is on the x-axis from negative 4 to positive 4.
–180°
–120°
140°
510°

Answer 1

-180

Explanation:

The measure of the angle on the attached figure is

There are two ways to measuring it

1. Counterclockwise: In this the sign is positive

So,

We can write

180°,

180°+360° = 540°,

180° + 2(360°) =180°+720° =900°,

2. Clockwise: In this, the sign is negative

So,

We can write

-180°,

-180° - 360° = -540°,

-180° - 2(360°) = -180° - 720° = -900°

the correct option is A.