Coterminal and Reference Angles

Front

What is a coterminal angle?

Back

Coterminal angles are angles that share the same terminal side when drawn in standard position. They can be found by adding or subtracting multiples of 360°.

Front

How do you find a coterminal angle for a given angle?

Back

To find a coterminal angle, add or subtract 360° until the angle is within the range of 0° to 360°.

Front

What is a reference angle?

Back

A reference angle is the acute angle formed by the terminal side of an angle and the x-axis. It is always positive and less than or equal to 90°.

Front

How do you find the reference angle for an angle in standard position?

Back

To find the reference angle, subtract the angle from 180° if it is in the second quadrant, subtract 180° if it is in the third quadrant, or subtract the angle from 360° if it is in the fourth quadrant.

Front

What quadrant is -500° in?

Back

-500° is in the third quadrant.

Front

What quadrant is -700° in?

Back

-700° is in the first quadrant.

Front

Find a coterminal angle to 45°.

Back

405° is a coterminal angle to 45°.

Front

What is the reference angle for 63°?

Back

The reference angle for 63° is 63°.

Front

What is the standard position of an angle?

Back

Standard position is when the initial side of the angle is on the positive x-axis.

Front

If an angle measures 150°, what is its reference angle?

Back

The reference angle for 150° is 30°.