Symbols and Symbols and SymmetrySymmetry

Learning ObjectivesLearning Objectives

Appreciate significance of symbolsAppreciate significance of symbols Know what symmetry is and Know what symmetry is and

recognise its beautyrecognise its beauty Be familiar with lines of symmetry Be familiar with lines of symmetry

and order of rotational symmetryand order of rotational symmetry Transform shapes on a grid to create Transform shapes on a grid to create

symmetrical symbolssymmetrical symbols

StarterStarter

There are several symbols displayed There are several symbols displayed around the roomaround the room

Your challenge is to match the group Your challenge is to match the group names with the symbols on your names with the symbols on your worksheetworksheet

Task OneTask One Did you manage to match them up correctly?Did you manage to match them up correctly?

Your first task will now be to calculate how many lines of symmetry and what order of rotational symmetry Your first task will now be to calculate how many lines of symmetry and what order of rotational symmetry each symbol haseach symbol has

SymmetrySymmetry Symmetry is something which is all around us, Symmetry is something which is all around us,

especially in especially in nature nature (click on link), and is (click on link), and is considered an important aspect of beautyconsidered an important aspect of beauty

What does symmetry mean?What does symmetry mean?

Can you write your own definition?Can you write your own definition?

WORKING DEFINITION: symmetry is a WORKING DEFINITION: symmetry is a characteristic of a figure or shape whereby characteristic of a figure or shape whereby reflection in a plane or rotation of the shape does reflection in a plane or rotation of the shape does not not appearappear to change it to change it

Lines of SymmetryLines of Symmetry

A line of symmetry is a line that A line of symmetry is a line that divides a figure into two halves that divides a figure into two halves that are mirror images of each otherare mirror images of each other

Shapes may have several lines of Shapes may have several lines of symmetry symmetry

Lines of Symmetry TricksLines of Symmetry Tricks

One good trick is to see how many One good trick is to see how many different ways you can fold a shape in different ways you can fold a shape in halfhalf

A second trick is to use a mirror to A second trick is to use a mirror to see how many ways you can make the see how many ways you can make the figure appear like the originalfigure appear like the original

Which letters of the alphabet are Which letters of the alphabet are symmetrical?symmetrical?

Order of Rotational Order of Rotational SymmetrySymmetry

What the heck is this all about?What the heck is this all about?

The rotational symmetry of an object is The rotational symmetry of an object is determined by how many times it can be determined by how many times it can be rotated about its centre point and appear to rotated about its centre point and appear to be the same before returning to its original be the same before returning to its original positionposition

Watch this Watch this animation animation to help you understand to help you understand what we are talking about. The shape in the what we are talking about. The shape in the animation has rotational symmetry to the animation has rotational symmetry to the order of 4.order of 4.

Task OneTask One

Now that we know what lines of Now that we know what lines of symmetry and order of rotational symmetry and order of rotational symmetry is all about we can return symmetry is all about we can return to our original task:to our original task:

How many lines of symmetry do our How many lines of symmetry do our symbols have?symbols have?

What order of rotational symmetry do they What order of rotational symmetry do they have?have?

Results - Did you get the Results - Did you get the same?same?

Lines of Lines of SymmetrySymmetry

Order of Order of Rotation Rotation SymmetrySymmetry

Star of DavidStar of David 66 66

Catholic Catholic CrossCross

11 00

Trade UnionsTrade Unions 11 00

WatchtowerWatchtower 11 00

Gypsy WheelGypsy Wheel 3232 1616

SwastikaSwastika 00 44

Disabled SignDisabled Sign 00 00

Task 2Task 2 We have been looking at various existing We have been looking at various existing

symbols, but how about making our own symbols, but how about making our own symmetrical symbols?symmetrical symbols?

Make your own symmetrical symbol (related Make your own symmetrical symbol (related to suffering and survival) into a displayto suffering and survival) into a display

TIP: Draw a cross on a blank sheet of paper or TIP: Draw a cross on a blank sheet of paper or grid paper and use a mirror to make grid paper and use a mirror to make reflections of your shape in each of the 4 reflections of your shape in each of the 4 quadrants, or use tracing paper and rotate quadrants, or use tracing paper and rotate your shape about the originyour shape about the origin

ExampleExample

PlenaryPlenary

In groups, write down 3 things that you In groups, write down 3 things that you have learnt this lessonhave learnt this lesson

Did we meet our learning objectives?Did we meet our learning objectives? Appreciate significance of symbolsAppreciate significance of symbols Know what symmetry is and recognise its Know what symmetry is and recognise its

beautybeauty Be familiar with lines of symmetry and order of Be familiar with lines of symmetry and order of

rotational symmetryrotational symmetry Transform shapes on a grid to create Transform shapes on a grid to create

symmetrical symbolssymmetrical symbols