9.3 – Perform Reflections
Reflection: Transformation that uses a line like a mirror to reflect an image Line of Reflection: Mirror line in a reflection
A reflection in a line m maps every point P in the plane to a point , such that: If P is not on m, then m is the perpendicular bisector of If P is on m, then
Reflect point P(5, 7) in the given line. x – axis P(5, 7) becomes P A reflection in the x-axis changes (x, y) into _______ (x, –y)
Reflect point P(5, 7) in the given line. y – axis P(5, 7) becomes P A reflection in the y-axis changes (x, y) into _______ (–x, y)
Reflect point P(5, 7) in the given line. y = x P(5, 7) becomes P A reflection in the y = x changes (x, y) into _______ (y, x)
Graph the reflection of the polygon in the given line. x – axis
Graph the reflection of the polygon in the given line. y – axis
y = x (–1 , –3) (–3, –1) (2, –4 ) (–4, 2) (3, 0) (0, 3) Graph the reflection of the polygon in the given line. y = x (–1 , –3) (–3, –1) (2, –4 ) (–4, 2) (3, 0) (0, 3)
Graph the reflection of the polygon in the given line. x – axis
Graph the reflection of the polygon in the given line. x = –1
Graph the reflection of the polygon in the given line.
9.4 – Perform Rotations
Rotation: Transformation that turns a figure about a fixed point Center of Rotation: The point that the rotation happens around Angle of Rotation: Degree the figure is rotated counterclockwise
A rotation about a point P through an angle of x° maps every point Q in the plane to a point such that: If Q is not the center of rotation, then and x° Q P
A rotation about a point P through an angle of x° maps every point Q in the plane to a point such that: If Q is the center of rotation, then Q
1. Match the diagram with the angle of rotation. B. 90°
1. Match the diagram with the angle of rotation.
1. Match the diagram with the angle of rotation.
Counter-clockwise degree of rotation: _______ 180° State if the rotation is 90°, 180°, or 270° counter-clockwise. Counter-clockwise degree of rotation: _______ 180°
Counter-clockwise degree of rotation: _______ 90° State if the rotation is 90°, 180°, or 270° counter-clockwise. Counter-clockwise degree of rotation: _______ 90°
Counter-clockwise degree of rotation: _______ 270° State if the rotation is 90°, 180°, or 270° counter-clockwise. Counter-clockwise degree of rotation: _______ 270°
6. Find the value of each variable in the rotation. x = 4 z = 3 y = z + 2 y = 3 + 2 y = 5
6. Find the value of each variable in the rotation. 4s = 24 s = 6 r = 2s – 3 r = 2(6) – 3 r = 12 – 3 r = 9
HW Problems 9.3 9.4 593-594 602-605 WS 3-7, 9, 12 (Graph on worksheet) 3-8, 20, 21, 44-46 ROTATION WS 9.3 #7