Angles Needed for Rotations
To work with rotations, you need to be able to recognize angles of certain sizes and understand the basic workings of a unit circle.
You should be able to recognize and reproduce the approximate size of a right angle (90° angle), a 45° angle, a 30° angle and a 60° angle.
The radius of a unit circle is one (one unit).
Notice that degree movement on a unit circle goes in a counterclockwise direction.
You will want to remember the layout of the unit circle when you are graphing figures and their rotations.