Intuitive Notion of Rotation
A rotation is a transformation that turns a figure about a fixed point called the center of rotation. An object and its rotation are the same shape and size, but the figures may be turned in different directions.
Amusement rides, such as the ferris wheel and the swing, allow you to experience the concept of rotation.
Rotations can be seen in nature. The leaf on this plant illustrates the concept of a rotation. The center of rotation is the point where the leaf is attached to the stem.
Rotations can be seen in planetary movement.
In mathematics, the rotation of an object is called its image. If the original object was labeled with letters, such as polygon ABCDE, the image may be labeled with the same letters followed by a prime symbol, A’B’C’D’E’.
Rotations can occur in either a clockwise or counterclockwise direction.
This rotation is 90° counterclockwise.
A positive angle of rotation turns the figure counterclockwise, and a negative angle of rotation turns the figure in a clockwise direction. The figure does not change size.