1/22/14 Watch the following videos Tyler Tarver Shmoop Look through following notes the notes Practice the Animation on classzone.com Chapter 4: Transformations and Symmetry Assignment: Worksheet

Perform Congruence Transformations Geometry 4.8 Perform Congruence Transformations

Transformations: when you move or change a geometric figure in some way to produce a new figure. Image is what the new figure is called. Congruence Transformations: changing the position of a figure without changing its size or shape. There are 3 types of transformations. Translation: is when we move every point on the figure, the same distance and direction. Reflection: is when we use a line of reflection to create a mirror image of the original figure. Rotation: Turns a figure about a fixed point called the center of rotation

Coordinate Notation for a translation: (x,y) (x+a, y+b) Which shows that each point (x,y) of the blue figure is translated horizontally a units and vertically b units y x b a

Coordinate Notation for a Reflection : Reflection in the x-axis Reflection in the y-axis y (x,y) y (x,y) (-x,y) x x (x,-y) Multiply the y coordinate by -1 (x,y) (x,-y) Multiply the x coordinate by -1 (x,y) (-x,y)

Rotation 90 clockwise Rotation 60 counterclockwise rotation y y x x

Example: Name the type of transformation

Example Figure ABCD has the vertices A(-4, 3), B(-2, 4), C(-1, 1), and D(-3, 1). Sketch ABCD and its image after the translation (x, y)  (x+5, y-2).

Example Figure WXYZ has the vertices W(-1, 2), X(2, 3), Y(5, 0), and Z(1, -1). Sketch WXYZ and its image after the translation (x, y)  (x-1, y+3).

ExAMPLE Use coordinate notation to describe the translation. 5 units right, 3 units up 7 units left, 4 units down