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Rotations. 9-3. To describe a rotation , you need to know the center of rotation (a point), the angle of rotation (a positive number of degrees), and whether the rotation is clockwise or counterclockwise. You can use the following two rules to rotate a figure through x° about a point R:
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Rotations 9-3
To describe a rotation, you need to know the center of rotation (a point), the angle of rotation (a positive number of degrees), and whether the rotation is clockwise or counterclockwise. • You can use the following two rules to rotate a figure through x° about a point R: • The image of R is itself (that is R’ = R). • For any point V, RV’ = RV and m<VRV’ = x.
A regular polygon has a center that is equidistant from its vertices. • Segments that connect the center to the vertices divide the polygon into congruent triangles. • A composition of rotations about the same point is itself a rotation about that point. To sketch the image, add the angles of rotation to find the total rotation.