4/26 - Radians, Co-terminal, and Reference Angles

Front

What is a radian?

Back

A radian is a unit of angular measure used in mathematics. It is defined as the angle subtended at the center of a circle by an arc whose length is equal to the radius of the circle.

Front

How do you convert degrees to radians?

Back

Front

What is the formula to find co-terminal angles?

Back

To find co-terminal angles, add or subtract multiples of 360° (or 2π radians) to the given angle.

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 90°.

Front

Convert 180° to radians.

Back

Front

Back

330°.

Front

Convert 150° to radians.

Back

Front

If an angle is 270°, what is a co-terminal angle?

Back

-90° or 630°.

Front

What is the sine of 30°?

Back

Front

What is the cosine of 60°?

Back