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 size of a right angle
(90 degrees), a 45 degree angle, a 30 degree angle and a
60 degree angle.
NOTE:  A 60 degree angle is equal to two 30 degree angles.

Notice that the unit circle moves in a counterclockwise direction. 
You will want to remember the layout of the unit circle when you are graphing figures and their rotations.

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