1. ROTATIONAL SYMMETRY Highlights of Presentaton:
Order of rotational symmetry
Centre of rotational symmetry
Angle of rotational symmetry
Examples of shapes
Presented by: JYOTI SINGH TGT Maths
KV Mughalsarai (Varanasi region)

2. Rotational Symmetry
An object is said to possess rotational symmetry when it looks exactly the same after a rotation. The degree of rotational symmetry that an object has is known as its order.
The order of rotational symmetry that an object has is the number of times that it fits on to itself during a full rotation of 360 degrees.
Rotation turns the object about a fixed point which is know as centre of rotation.
PowerPoint XP or above is needed to view the rotations on this presentation.
During rotation the angle at which the object attains its original shape is called angle of rotation.

3. Rotational Symmetry
For shapes that have only “order 1” rotational symmetry a centre of rotation can be found anywhere within it.
For shapes that have “order 2” rotational symmetry or higher, a single centre of rotation can be located.
PowerPoint XP or above is needed to view the rotations on this presentation.
Order 1
Order 2
Order 3
Order 4

4. Rotational Symmetry
The order of rotational symmetry that an object has is the number of times that it fits on to itself during a full rotation of 360 degrees.
Order 1

5. Rotational Symmetry
The order of rotational symmetry that an object has is the number of times that it fits on to itself during a full rotation of 360 degrees. 2 1
Order 1
Order 2

6. Rotational Symmetry
The order of rotational symmetry that an object has is the number of times that it fits on to itself during a full rotation of 360 degrees. 2 1
Order 1
Order 2 3 2 1
Order 3

7. Rotational Symmetry
The order of rotational symmetry that an object has is the number of times that it fits on to itself during a full rotation of 360 degrees. 2 1
Order 1
Order 2 3 3 4 2 1 2 1
Order 4
Order 3

8. Rotational Symmetry
The figure attains its original shape at every turn of 120 degrees.This is the angle of rotation for given figure. 3
120 degrees turn
120 degrees turn 2 1
120 degrees turn
Order 3

9. Rotational Symmetry
This figure attains its original shape four times during the complete rotation each at an angle of 90 degrees .Angle of rotation is 90 degrees.
90 degrees turn
90 degrees turn 3 4 2 1
90 degrees turn
90 degrees turn
Order 4

10. NOW EXAMPLES OF ROTATIONAL SYMMETRY FOR POLYGONS

11. Regular Polygons Equilateral Triangle
An equilateral triangle has rotational symmetry of order ?
Regular Polygons

12. Equilateral Triangle
An equilateral triangle has rotational symmetry of order ?

13. Equilateral Triangle
An equilateral triangle has rotational symmetry of order ? 3 3 2 1

14. Square
A square has rotational symmetry of order ?
Square

15. Square
A square has rotational symmetry of order ?

16. Square
A square has rotational symmetry of order ? 4 3 4 2 1

17. Pentagon Regular Pentagon
A regular pentagon has rotational symmetry of order ?
Pentagon

18. Regular Pentagon
A regular pentagon has rotational symmetry of order ?

19. Regular Pentagon
A regular pentagon has rotational symmetry of order ? 5 5 4 1 3 2

20. Hexagon Regular Hexagon
A regular hexagon has rotational symmetry of order ?
Hexagon

21. Regular Hexagon
A regular hexagon has rotational symmetry of order ?

22. Regular Hexagon 6 A regular hexagon has rotational symmetry of order ?5 6 4 1 3 2

23. Octagon Regular Octagon
A regular octagon has rotational symmetry of order ?
Octagon

24. Regular Octagon 8 A regular octagon has rotational symmetry of order ?7 8 6 1 5 2 4 3

25. Rectangle
A rectangle has rotational symmetry of order ?
Rectangle

26. Rectangle
A rectangle has rotational symmetry of order ? 2 2 1

27. Parallelogram
A parallelogram has rotational symmetry of order ?

28. Parallelogram 2
A parallelogram has rotational symmetry of order ? 2 1

29. Isosceles Triangle
An isosceles triangle has rotational symmetry of order ?

30. Isosceles Triangle 1
An isosceles triangle has rotational symmetry of order ? 1

31. Scalene Triangle
An scalene triangle has rotational symmetry of order ?

32. Scalene Triangle 1
An scalene triangle has rotational symmetry of order ? 1

33. Isosceles Trapezium
An isosceles trapezium has rotational symmetry of order ?

34. Isosceles Trapezium
An isosceles trapezium has rotational symmetry of order ? 1 1

35. Trapezium
A trapezium has rotational symmetry of order ?

36. Trapezium 1
A trapezium has rotational symmetry of order ? 1

37. Kite
A kite has rotational symmetry of order ?

38. Kite 1
A kite has rotational symmetry of order ? 1

39. Rhombus
A rhombus has rotational symmetry of order ?

40. Rhombus 2
A rhombus has rotational symmetry of order ? 2 1

41. Questions 1 Rotational Symmetry
State the order of rotational symmetry for each shape below: 1 2 3 4
Order 6
Order 2
Order 3
Order 2 5 6 7 8
Order 1
Order 3
Order 2
Order 5 9 10 11 12
Questions 1
Order 4
Order 1
Order 6
Order 8