© t madas. we can extend the idea of rotational symmetry in 3 dimensions:

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Page 1: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Page 2: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

We can extend the idea of rotational symmetry in 3 dimensions:

Page 3: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

We can extend the idea of rotational symmetry in 3 dimensions:

We say that this solid has rotational symmetry,about the line shown.

This line is sometimes called axis of symmetry

The order of this rotational symmetry is 4,about the line shown

Page 4: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

In general in 3D space:A solid has rotational symmetry ifthe transformation of rotation about one or more axes, leave the solid unchanged

order 4

order 4

order 2order 2

If a solid has two or more axes of rotational symmetry which meet at a point, then the solid is said to have point symmetry.

Page 5: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

In general in 3D space:A solid has rotational symmetry ifthe transformation of rotation about one or more axes, leave the solid unchanged

infinite order

infinite axeswith order 2

infinite axesinfinite order

If a solid has two or more axes of rotational symmetry which meet at a point, then the solid is said to have point symmetry.

Page 6: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Is it possible to have rotational symmetry in 3D space without a single axes of rotational symmetry?

No axes of rotational symmetry?

Page 7: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Is it possible to have rotational symmetry in 3D space without a single axes of rotational symmetry?

No axes of rotational symmetry?

Page 8: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Page 9: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Look at the following shapesLabel them using the following code:

R = it has rotational symmetryN = no rotational symmetry

0 = no plane of symmetry1 = 1 plane of symmetry2 = 2 planes of symmetry3 = 3 planes of symmetry4 = 4 planes of symmetry etc

E.g. N2: no rotational symmetry, 2 planes of symmetry

Page 10: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Page 11: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Page 12: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Look at the following shapesLabel them using the following code:

R = it has rotational symmetryN = no rotational symmetry

0 = no plane of symmetry1 = 1 plane of symmetry2 = 2 planes of symmetry3 = 3 planes of symmetry4 = 4 planes of symmetry etc

E.g. N2: no rotational symmetry, 2 planes of symmetry

Page 13: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

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Page 14: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Page 15: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

Page 16: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas

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Page 17: © T Madas. We can extend the idea of rotational symmetry in 3 dimensions:

© T Madas