Warm Up Draw an example of a reflection: Draw an example of a figure that has one or more lines of symmetry: Find the new coordinates of the image after being reflection over the x-axis:(2, -3)(5, -4)(3, -5)
Chapter 13.6 Rotation Center of rotation Angle of rotation
Determine angle of rotation
Using coordinate notation to describe a 90 degree rotation 90° clockwise rotation (x,y) (y, -x) *Switch the coordinates, then multiply the new y- coordinate by -1
Using coordinate notation to describe a 90 degree rotation 90° counterclockwise rotation (x,y) (-y, x) *Switch the coordinates, then multiply the new y- coordinate by -1
Using coordinate notation to describe a 180 degree rotation 180° clockwise rotation (x,y) (-y, -x) *simply multiply each coordinate by -1
Rotational symmetry A figure has rotational symmetry if a rotation of 180° or less clockwise (or counterclockwise) about its center produces an image that fits exactly on the original figure.
Homework Page 744 #’s 1-18