Rotational Symmetry

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Rotational Symmetry
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Rotational Symmetry

• If, when you rotate a shape, it looks exactly the
  same as it did in its original position, then we
  say that the shape has rotational symmetry.
• This square has rotational symmetry.

• It looks exactly the same four times in a full
  turn.
• It has rotational symmetry order 4.

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Rotational Symmetry

• Does this rectangle have rotational symmetry?

Yes, it fits!
No, it doesnt fit
No, it doesnt fit
Yes, it fits!
Click to rotate the rectangle.

• It looks exactly the same twice in a full turn.
• It has rotational symmetry order 2.

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Rotational Symmetry in the Alphabet

• Which letters have rotational symmetry?

Click to see the answers.
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
Order 2
Order 2
Order 2
Order 2
S
T
U
V
W
X
Y
Z
Order 2
Order 2
Order 2
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Rotational Symmetry all around us

• Which road signs have rotational symmetry?

Click to see the answers.
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Rotational Symmetry all around us

• Click to see the road signs with rotational
  symmetry.

Order 3
Order 2
Order 2
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Rotational Symmetry all around us

• Click to see more road signs with rotational
  symmetry.

Order 4
Order 3
Order 2
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Rotational Symmetry all around us

• Click to see more road signs with rotational
  symmetry.

Order 3
Order 2
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Rotational Symmetry with Pentominoes

• If you dont know what a pentomino is, then click
  here.
• If you have done the pentominoes activity before,
  then you will know what a pentomino is and how
  many different pentominoes there are.
• Here they are ...

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Rotational Symmetry with Pentominoes

• Which Pentominoes have rotational symmetry?
• Sort them according to their rotational symmetry.

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Rotational Symmetry with Pentominoes
Rotational Symmetry Order 2
Rotational Symmetry Order 4
Click to start sorting
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Rotational Symmetry with 7-Pin Polygons

• If you dont know what a 7-pin polygon is, then
  click here.
• If you have done the 7-pin polygons activity
  before, then you will know what a 7-pin polygon
  is and how many different ones there are.
• Here they are ...

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Rotational Symmetry with 7-Pin Polygons

• Which 7-Pin Polygons have rotational symmetry?
• Sort them according to their rotational symmetry.

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Rotational Symmetry with 7-Pin Polygons
Rotational Symmetry Order 2
Rotational Symmetry Order 6
Rotational Symmetry Order 3
Click to start sorting
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Now you know all about rotational symmetry!END
OF PRESENTATION
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Pentominoes

• A pentomino is made out of five squares that are
  connected along at least one edge.

These are NOT pentominoes.
Here is an example of a pentomino.
How many different pentominoes can you find?
Click here to return to line symmetry.
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7-Pin Polygons

• Here is an arrangement of 7 pins.

A 7-pin polygon is a closed shape with straight
sides with corners on the pins.
Here are some examples of 7-pin polygons.
How many different 7-pin polygons can you find?
Click here to return to line symmetry.
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END OF PRESENTATION