turning a figure about a point (center of rotation) for a certain number of degrees ( ∠ of...
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TransformationsRotations, Dilations
Vocabulary Today
Objectives today…
Turning a figure about a point
(center of rotation) for a certain number
of degrees (∠ of rotation)
counter-clockwise
1 3 -13 -5-1 -5
-1 -3-5 -3-5 1
1
y -x
-x -y
-y x
Technology Break
5 min
clockwise
1 1 35 35 -1
1 3 -13 -5-1 -5
y -x
-x -y-y x
Using a scale factor to make a
figure larger or smaller (needs to
maintain the same shape!)great
er0 1
-4 -4-2 44 1
ENLARGEMENT
2x 2y
(4/2, 3/2)
(2, 1.5)(7/2, -1/2)
(3.5, -.5)(2/2, -2/2)
(1, -1)
A’
B’C’
REDUCTION
(2, 6)(3.5, -2)(1, -4)
A’
B’C’ NEITHER. NOT A
DILATION
Technology Break
5 min
Look at how a point changes3*s = 2 and 6*s = 4s = 2/3 and s = 4/6
M’ (8, -2)A’ (18, -4)T’ (6, 12)H’ (0, 0)
s = 2
(x, y) (2x, 2y)
2/3
Vocabulary Revisited
HomeworkRotations and Dilations Practice
Shark Story
Shark Story Graphs
1st Graph: › Original Shark› Translated Shark› Reflected Shark
2nd Graph: › Shark Lenny› His hat and
rotated hat 3rd Graph:
› Original Shark› His hat and
rotated hat
Label your points› Original: A, B, C,
…› Translated: A’, B’,
C’,…› Reflected: A’’, B’’,
C’’, …› Shark Lenny you
may say A, B, C…(since on separate graph)
› Rotated Hats: Z’, Y’, X’…
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