Maths: GeometryFriday 8th May 2020

Lines of Symmetry

Weekly outline- What we are doing this week

Monday- Identify AnglesTuesday- Compare and order AnglesWednesday- Classify TrianglesThursday- QuadrilateralsFriday- Lines of Symmetry

Friday

Today we are going to learn about lines of symmetry in shapes.

Write today’s date and LO in your book08.05.20LO: Find lines of symmetry in shapes

Key Vocabularyline, symmetrical, equal, orientation

Warm upSet a timer and see how long it takes you to answer these times table facts. Each day the same facts will be on the warm up slide… but in a different order. Can you get faster each day?4x6= 7x4=3x5= 10x11=5x6= 8x5=7x3= 12x3=9x2= 9x5=2x11= 6x6=

Warm up AnswersSet a timer and see how long it takes you to answer these times table facts. Each day the same facts will be on the warm up slide… but in a different order. Can you get faster each day?4x6= 24 7x4= 283x5= 15 10x11= 1105x6= 30 8x5= 407x3= 21 12x3= 369x2= 18 9x5= 452x11= 22 6x6= 36

What do you notice about all of these pictures?

What do you notice about all of these pictures?They are all symmetrical.

What is symmetry?

https://www.bbc.co.uk/bitesize/topics/zrhp34j/articles/z8t72p3

Watch this BBC bitesize to learn about symmetry.

Activity One:

Here is a shape which has a line of symmetry showing that it is the same on both sides.

Draw these shapes in your book. Draw all the lines of symmetry on these shapes (Remember they could be horizontal, vertical or diagonal).

What about this shape?

Activity 1: Answers

Here is a shape which has a line of symmetry showing that it is the same on both sides.

Draw all the lines of symmetry on these shapes (Remember they could be horizontal, vertical or diagonal).

What about this shape? INFINITY(It goes on forever)

Activity Two:

Draw a table in your book that looks like this. It doesn’t need to be the whole page. Sort these shapes according to how many lines of symmetry they have. I’ve done two

for youOne line of symmetry or less More than one line of symmetry

Activity Two: Answers

One line of symmetry or less More than one line of symmetry

Activity ThreeDraw a Venn diagram like the one below. Put the shapes in the correct places on the Venn diagram.

4 sides or more

1 line of symmetry

Activity Three: AnswersPut the shapes in the correct places on the Venn diagram.

4 sides or more

1 line of symmetry

Activity Four

Where is the line of symmetry in these shapes? You could draw them in your book to see where the lines of symmetry are.

What do you notice about all three lines of symmetry?What do you notice about all three shapes?Does the orientation (position) of the shape affect the lines of symmetry?

Activity Four: Answers

Where is the line of symmetry in these shapes?

What do you notice about all three lines of symmetry? They are the same.What do you notice about all three shapes? They are the same just turned around.Does the orientation (position) of the shape affect the lines of symmetry? No

Activity Five Challenge

Ben says,

Is Ben correct? Prove it.

A rectangle has 2 lines of symmetry unless you change its orientation (change the way it is

facing).

Activity 5: Answers

Challenge

Always, Sometimes, Never

The number of lines of symmetry is the same as the number of sides the shape has. Is this statement always, sometimes or never true? Prove it.

Challenge: AnswersAlways, Sometimes, Never

The number of lines of symmetry is the same as the number of sides the shape has.Is this statement always, sometimes or never true?Prove it.

Sometimes –

1 sided shape but infinity amounts of lines of symmetry.

4 sided shape and has 4 lines of symmetry.

Fantastic work Year Four

Great work on Geometry this week.If you have grid paper at home you could make a symmetrical picture.

If you don’t, try making an artwork with the geometry knowledge you have learnt this week: angles, triangles, quadrilaterals and symmetry.