1. The world of technology
welcome to
techni C
lass
In MATHEMATICS
The world of technology
______________________________

3. Modified by Nagaraj Rotational Symmetry 7 2 1 5
© 2007 All rights reserved 5 7 2 1
Modified by Nagaraj

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

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 3600
Order 1

6. Rotational Symmetry 2
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 3600 1
Order 1
Order 2

7. Rotational Symmetry 2
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 3600 1
Order 1
Order 2 3 2 1
Order 3

8. 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 2 1
Order 1
Order 2 3 3 4 2 1 2 1
Order 4
Order 3

9. Rotational Symmetry
What is the order of rotational symmetry of the shape below?

10. Rotational Symmetry
What is the order of rotational symmetry of the shape below? 5 4 1 3 2
Order 5

11. Rotational Symmetry
What is the order of rotational symmetry of the shape below?

12. Rotational Symmetry
What is the order of rotational symmetry of the shape below? 6 5 1 2 4 3
Order 6

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

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

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

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

17. Square
A square has rotational symmetry of order ?

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

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

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

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

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

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

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

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

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

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

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

29. Parallelogram Parallelogram
A parallelogram has rotational symmetry of order ?
Parallelogram

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

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

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

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

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

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

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

37. Trapezium
A trapezium has rotational symmetry of order ?
Trapezium

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

39. Kite
A kite has rotational symmetry of order ?
Kite

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

41. Rhombus
A rhombus has rotational symmetry of order ?
Rhombus

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

43. Ellipse
An ellipse has rotational symmetry of order ?
Ellipse

44. Ellipse 2
An ellipse has rotational symmetry of order ? 1 2
Ellipse

45. 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
Order 4
Order 1
Order 6
Order 8

46. Rotational Symmetry
State the order of rotational symmetry for each shape below: 13 14 15 16
Order 4
Order 1
Order 2
Order 5 17 18 19 20
Order 2
Order 4
Order 6
Order 3 21 22 23 24
Order 5
Order 4
Order 3
Order 1

47. Now..it’s the time for…
The
POWER-TEST
To ignite your minds..

48. Evaluation @ First, Observe the given Picture carefully.
@ Try to Imagine the rotation
@ Concentrate on the inner designs also
@ Each question carries ‘1m’ as usual
@ Time limit for each Work sheet is ‘5 min.,’ only
# WRITE ONLY THE ORDER OF ROTATIONAL SYMMETRY IN THE GIVEN BOXES

49. Worksheet 1 Rotational Symmetry
State the order of rotational symmetry for each shape below: 1 2 3 4 5 6 7 8 9 10
Worksheet 1

50. Worksheet 2 Rotational Symmetry
State the order of rotational symmetry for each shape below: 11 12 13 14 15 16 17 18 19 20
Worksheet 2

51. Credits & Acknowledges !
The master trainer. Mr. N. Uma Srinivas
MS Office
MS Encarta
Perspector panel
VIPS Knowledge Centre.