Rotational Symmetry

1. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 1
March 10, 2014
May 5­7:56 AM
Objective: graph rotations and identify rotational symmetry
Graph the triangle.
A(1,3), B(4, 1), C(3, ­2)
Bellwork

2. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 2
March 10, 2014
May 6­7:57 AM
page 505 # 1­
1. None
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4. 12. No, a figure and its reflection are congruent.
13.
14.
6.
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9.
D
E
T T'
E'D'
K N
T U
N'
K'
T'U'
5.
10.
11.

3. 9.10 rotational symmetry
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15.
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4. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 4
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rotation ­ turns a figure about a fixed point (center of rotation)
angle of rotation ­ angle measure of the rotation
90o
P Q
R
R' Q'
Center of rotation
A figure and its rotation image are congruent.
All rotations that we will do will be counterclockwise.

5. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 5
March 10, 2014
May 5­8:05 AM
Find the vertices of the image of ΔACB after a rotation of 180o about the origin.
A
B
C

6. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 6
March 10, 2014
May 5­8:08 AM
A figure has rotational symmetry if you can rotate it 180 o, or less, so that its image matches the original figure.
The angle (or its measure) through which the figure rotates is the angle of rotation.
A
A'Angle of Rotation is 360o ÷

7. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 7
March 10, 2014
May 5­8:48 AM
Judging from appearance, state whether the flower has rotational symmetry.
If so, what is the angle of rotation.
1
2
3

8. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 8
March 10, 2014
May 5­8:50 AM
Does the figure have rotational symmetry? What is the angle of rotation?

9. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 9
March 10, 2014
May 5­8:52 AM
9.10
HW
pg. 488 #7­23
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10. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 10
March 10, 2014
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11. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 11
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12. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 12
March 10, 2014
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13. 9.10 rotational symmetry
HW pg. 488 #7­23 odds 13
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Apr 11­8:19 AM