The world of technology welcome to techni C lass In MATHEMATICS The world of technology ______________________________
Modified by Nagaraj Rotational Symmetry 7 2 1 5 © 2007 All rights reserved 5 7 2 1 Modified by Nagaraj
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
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
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
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
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 . 2 1 Order 1 Order 2 3 3 4 2 1 2 1 Order 4 Order 3
Rotational Symmetry What is the order of rotational symmetry of the shape below?
Rotational Symmetry What is the order of rotational symmetry of the shape below? 5 4 1 3 2 Order 5
Rotational Symmetry What is the order of rotational symmetry of the shape below?
Rotational Symmetry What is the order of rotational symmetry of the shape below? 6 5 1 2 4 3 Order 6
Equilateral Triangle An equilateral triangle has rotational symmetry of order ?
Equilateral Triangle An equilateral triangle has rotational symmetry of order ?
Equilateral Triangle An equilateral triangle has rotational symmetry of order ? 3 3 2 1
Square A square has rotational symmetry of order ? Square
Square A square has rotational symmetry of order ?
Square A square has rotational symmetry of order ? 4 3 4 2 1
Pentagon Regular Pentagon A regular pentagon has rotational symmetry of order ? Pentagon
Regular Pentagon A regular pentagon has rotational symmetry of order ?
Regular Pentagon A regular pentagon has rotational symmetry of order ? 5 5 4 1 3 2
Hexagon Regular Hexagon A regular hexagon has rotational symmetry of order ? Hexagon
Regular Hexagon A regular hexagon has rotational symmetry of order ?
Regular Hexagon 6 A regular hexagon has rotational symmetry of order ? 5 6 4 1 3 2
Octagon Regular Octagon A regular octagon has rotational symmetry of order ? Octagon
Regular Octagon 8 A regular octagon has rotational symmetry of order ? 7 8 6 1 5 2 4 3
Rectangle A rectangle has rotational symmetry of order ? Rectangle
Rectangle A rectangle has rotational symmetry of order ? 2 2 1
Parallelogram Parallelogram A parallelogram has rotational symmetry of order ? Parallelogram
Parallelogram 2 A parallelogram has rotational symmetry of order ? 2 1
Isosceles Triangle An isosceles triangle has rotational symmetry of order ?
Isosceles Triangle 1 An isosceles triangle has rotational symmetry of order ? 1
Scalene Scalene Triangle An scalene triangle has rotational symmetry of order ? Scalene
Scalene Triangle 1 An scalene triangle has rotational symmetry of order ? 1
Isos Trapezium Isosceles Trapezium An isosceles trapezium has rotational symmetry of order ? Isos Trapezium
Isosceles Trapezium An isosceles trapezium has rotational symmetry of order ? 1 1
Trapezium A trapezium has rotational symmetry of order ? Trapezium
Trapezium 1 A trapezium has rotational symmetry of order ? 1
Kite A kite has rotational symmetry of order ? Kite
Kite 1 A kite has rotational symmetry of order ? 1 Kite
Rhombus A rhombus has rotational symmetry of order ? Rhombus
Rhombus 2 A rhombus has rotational symmetry of order ? 2 1
Ellipse An ellipse has rotational symmetry of order ? Ellipse
Ellipse 2 An ellipse has rotational symmetry of order ? 1 2 Ellipse
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
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
Now..it’s the time for… The POWER-TEST To ignite your minds..
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
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
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
Credits & Acknowledges ! The master trainer. Mr. N. Uma Srinivas MS Office MS Encarta www.whiteboardmath.com www.teachingideas.com www.pppst.com Perspector panel VIPS Knowledge Centre.