Coterminal angles: are angles in standard position (angles with the initial side on the positive x-axis) that have a common terminal side. For example, the angles 30°, –330° and 390° are all coterminal (see figure 2.1 below).

How do you know if a angle is Coterminal?

Coterminal Angles are angles who share the same initial side and terminal sides. Finding coterminal angles is as simple as adding or subtracting 360° or 2π to each angle, depending on whether the given angle is in degrees or radians.

Do Coterminal angles have the same reference angles?

If two angles in standard position have the same terminal side, they are called coterminal angles. ... A reference angle is always positive and is always less than 90º. Remember: The reference angle is measured from the terminal side of the original angle "to" the x-axis (not "to" the y-axis).