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Perform Congruence Transformations
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Transformations
Preimage ­ original figure
Image ­ new figure
3 Basic Transformations
1. Reflection ­ mirror image
2. Rotation ­ turn
3. Translation ­ slide
Name the type of transformation.
1.
2.
3. 2
Rigid ­ Every image to preimage
Isometry ­ A transformation in a plane that preserves length and angle measure
Example:
Motion Rule: (x,y) (x+2, y+3) Graph ABC
A (­2, 1)
B (1,1)
C (­1,2)
Find
A'B'C'
A' ( , )
B' ( , )
C' ( , )
Be sure to label axes and points!
Which type of transformation is this?
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You are cutting figures out of paper. Use a reflection in the x­axis to draw the other half of the figure.
(x,y) ______
(­1,0) ______
(1,1) _______
(2,4) _______
(3,1) _______
(7,0) _______
Multiply the __________ of each vertex by ­1 to find the corresponding vertex in the image.
Figure FGHJ has the vertices F(0,2), G(2,3), and J(0,­2). Sketch FGHJ and its image after (a) the translation (x,y) (x­3, y+1) and (b) a feflection in the y­
axis.
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Graph JK and LM. Tel whether LM is a rotation of JK about the origin. If so, give the angle and direction of rotation.
a.) J(3,1), K(1,4), L(­1,3), M(­4,1)
b.) J(2,1), K(­1,5), L(1,1), M(2,5)
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Homework:
p. 276­279/1, 3­5, 10­16E, 17, 20, 21, 26­31, 33­36
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