The Unit Circle

Concept

Coterminal Angles

Two or more angles in standard position with the same terminal side are called coterminal angles. For example, angles measuring 50^(∘), 410^(∘), and - 310^(∘) are coterminal angles.

Angles of 50, 410, and -310 degrees in standard position

If two angles are coterminal, the measure of one of them is equal to the measure of the other angle plus a multiple of 360^(∘), or in the case of radians, plus a multiple of 2π. Therefore, for any angle θ and any integer n, coterminal angles can be found by the following formula.

Degrees: & θ + n* 360 Radians: & θ + n* 2 π

Exercises
Edit Lesson