Rotational Symmetry 5 7 2 1

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

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 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 ?

This shape has rotational symmetry every 120 degrees. Equilateral Triangle An equilateral triangle has rotational symmetry of order ? 3 3 2 1 This shape has rotational symmetry every 120 degrees.

Square A square has rotational symmetry of order ? Square

Square A square has rotational symmetry of order ?

A square has rotational symmetry every 90 degrees. A square has rotational symmetry of order ? 4 3 4 2 1 A square has rotational symmetry every 90 degrees. 360 ÷4 = 90

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 A regular pentagon has rotational symmetry 5 times. 360 degrees divide by 5 means it matches up every 72 degrees.

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

Regular Hexagon A regular hexagon has rotational symmetry of order ?

The hexagon has rotational It has symmetry eveyy 60 degrees Regular Hexagon A regular hexagon has rotational symmetry of order ? 6 5 6 The hexagon has rotational Symmetry 6 times. 360 ÷6. It has symmetry eveyy 60 degrees 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 The regular octagon has 8 points of rotational symmetry. It matches up 360÷8 or every 45 degrees ! 6 1 5 2 4 3

Rectangle A rectangle has rotational symmetry of order ? Rectangle

Rectangle 2 A rectangle has rotational symmetry of order ? 2 1 This rectangle is not a regular polygon. It will show rotational symmetry only twice. 360 degrees÷2 every 180 degrees

Parallelogram Parallelogram A parallelogram has rotational symmetry of order ? Parallelogram

Parallelogram 2 A parallelogram has rotational symmetry of order ? 2 1 How many degrees must this parallelogram rotate before it shows symmetry?

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 Trapezoid A isocelese trapezoid has rotational symmetry of order ? Isos Trapezium

Isosceles Trapezium An isosceles trapezioid has rotational symmetry of order ? 1 1 Since there is no symmetry until it has rotated the entire 360 degrees, the order of symmetry is one.

Trapezium Right Trapezoid A trapezium has rotational symmetry of order ? Trapezium

Right Trapezoid 1 A right trapezoid has rotational symmetry of order ?

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