Chapter 6
Lesson 3
Objective
Essential
Question
Rotations
 Graph rotations on the coordinate plane
 What is the difference between rotating a figure
about a given point that is a vertex and rotating
the same figure about the origin if the rotation is
less than 360°?
Rotation
 A transformation where a figure is turned about
a fixed point.
Center of
Rotation
 A fixed point around which shapes move in a
circular motion to a new position.
Math symbols
 (x, y)
 (x, y)
 (x, y)
(y, -x) 90° rotation
(-x, -y) 180° rotation
(-y, x) 270° rotation
Rotating a Graph JKL with vertices J(3, 1), K(3, -3), and
Figure L(0, -3) Graph its image in a counterclockwise rotation
of 90 about vertex J. Then give its coordinates for its
vertices for the image.
L’
J’
K’
J
L
K
Coordinates of new image
A’(3, 1), B’(-1, 1), C’(-1, 4)
Rotating about Triang ABC has vertices A(-4, 1), B(-1, 4), and C(-2, 1).
the origin Graph the figure and its image after a counter
clockwise rotation of 180° about the origin. Then give
the coordinates of the vertices for A’B’C’.
B
A
C
C’
A’
B’
Clockwise rotation 180°
(-x, -y)
X(-1)
y(-1)
A(-4, 1) -4(-1)
1(-1)
B(-1, 4) -1(-1)
4(-1)
C(-2, 1) -2(-1)
1(-1)
A’ (4, -1), B’(1, -4), C’(2, -1)
A’ (4, -1)
B’(1, -4)
C’(2, -1)
Summary