Radians & the Unit Circle REVIEW

Front

What is a radian?

Back

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

Front

How do you convert degrees to radians?

Back

Front

What is the unit circle?

Back

The unit circle is a circle with a radius of 1 centered at the origin of a coordinate plane, used to define trigonometric functions.

Front

What is the relationship between coterminal angles?

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° or 2π radians.

Front

Back

Front

How do you find the terminal side of an angle?

Back

To find the terminal side of an angle, start at the positive x-axis and rotate counterclockwise for positive angles or clockwise for negative angles.

Front

What is the measure of -940 degrees in standard position?

Back

To find the equivalent angle in standard position, add 360° repeatedly until the angle is between 0° and 360°. -940° + 3(360°) = 140°.

Front

In which quadrant is an angle of -700° located?

Back

An angle of -700° is located in the 1st quadrant.

Front

What are the positive and negative coterminal angles of -225°?

Back

The positive coterminal angle is 135° and the negative coterminal angle is -585°.

Front

What is the formula to find the reference angle?

Back

The reference angle is found by taking the absolute value of the angle and subtracting it from 180° or 360° depending on the quadrant.