1. Draw circles, identify and study polygons, especially triangles
Shape
Draw circles, identify and study polygons, especially triangles
Objectives
Day 1
Use a compass to draw circles to given radii.
Day 2
Draw different polygons; identify their properties.
Day 3
Describe, name and sort triangles, identifying their properties.
Before teaching, be aware that:
On Day 1 you will need a board compass to show children how to set the radius and draw a circle, notes for this are with Slide 9, along with follow up group activities.
On Days 2 and 3 children will need mini-whiteboards and pens.
Year 4

2. Draw circles, identify and study polygons, especially triangles
Shape
Draw circles, identify and study polygons, especially triangles
Starters
Day 1
2-D shapes (pre-requisite skills)
Day 2
Telling the time (simmering skills)
Day 3
Complete symmetrical drawings (simmering skills)
Choose starters that suit your class by dragging and dropping the relevant slide or slides below to the start of the teaching for each day.
Year 4

3. Shape Draw circles, identify and study polygons, especially triangles
Starter
2-D shapes (pre-requisite skills)
Pre-requisite skills – to use this starter, drag this slide to the start of Day 1
Hide a 2-D shape in a feely bag and give three clues about it. Children draw the shape and show their whiteboards. Reveal the shape to confirm if they are correct. Repeat, but with a child taking your role. Include regular and irregular pentagons, hexagons and octagons. Encourage children to use the correct mathematical vocabulary when giving the clues.
Year 4

4. Draw circles, identify and study polygons, especially triangles
Shape
Draw circles, identify and study polygons, especially triangles
Starter
Telling the time
Simmering skills – to use this starter, drag this slide to the start of Day 2
Choose a child to move the hands on an analogue clock to make a time. The child holds the clock up to the class. Ask children to write the time on their whiteboards. Choose children to read out the time. Repeat with new children and times.
Year 4

5. Shape Draw circles, identify and study polygons, especially triangles
Starter
Complete symmetrical drawings
Simmering skills – to use this starter, drag this slide to the start of Day 3
Draw a line down the centre of the board. This is the line of symmetry. Choose a child to draw half a picture on one side of the line. Ask children to draw a line on their whiteboards, make a sketch-copy of the drawing and complete it to make it symmetrical. Repeat with other children and other drawings.
Year 4

6. Draw circles, identify and study polygons, especially triangles
Shape
Draw circles, identify and study polygons, especially triangles
Objectives
Day 1
Use a compass to draw circles to given radii.
Year 4

7. Day 1: Use a compass to draw circles to given radii.
Let’s mark the centre and draw a straight line to the circumference.
The distance all the way around a circle is called the circumference.
That distance is called the radius of the circle, let’s measure it…
Year 4

8. Let’s draw and measure another radius…
Day 1: Use a compass to draw circles to given radii.
… and another…
7cm
What do you notice?
Year 4

9. Day 1: Use a compass to draw circles to given radii.
Let’s draw another circle and measure the radius…
How far is it across the circle, along a line right through the centre?
Show children a compass. Explain that a compass can be used to draw circles. Demonstrate what happens when we draw a circle ‘free-hand’.
How could the radius help us to draw a circle? Children discuss the possibilities.
Model how to set the compass to 10cm by positioning it on a ruler. What will the radius of my circle be? 10cm.
Draw the circle and then ask a child to check the radius to confirm.
How far is it across the circle, along a line right through the centre? 20cm. We call this the diameter of the circle. It is double the radius.
Repeat with other radii.
Children can now go on to do differentiated GROUP ACTIVITIES. You can find Hamilton’s group activities in this unit’s TEACHING AND GROUP ACTIVITIES download.
WT: Use compasses to draw circles with measured radii (with support).
ARE: Use compasses to draw circles with measured radii.
GD: Use compasses to draw circles with measured radii, plus Challenge.
It is always double the radius. Can you see why?
We call this the diameter of the circle.
Year 4

10. The Practice Sheet on this slide is suitable for most children.
Differentiated PRACTICE WORKSHEETS are available on Hamilton’s website in this unit’s PROCEDURAL FLUENCY box.
WT/ ARE/ GD: Drawing circles Sheet 1.
Challenge
Year 4

11. Draw circles, identify and study polygons, especially triangles
Shape
Draw circles, identify and study polygons, especially triangles
Objectives
Day 2
Draw different polygons; identify their properties.
Year 4

12. Day 2: Draw different polygons; identify their properties.
A closed shape with 7 straight sides and 7 vertices is called a heptagon.
How many sides has a 50p piece?
The sides on a 50p coin and on this 20p are very slightly curved and the corners are rounded.
The shapes we are going to draw today will have straight sides only!
Year 4

13. All 7 sides are the same length and all angles are the same size.
Day 2: Draw different polygons; identify their properties.
This is a
regular heptagon.
All 7 sides are the same length and all angles are the same size.
Draw your own irregular heptagon on your whiteboard.
Try to make it look different from your neighbour’s.
Children can now go on to do differentiated GROUP ACTIVITIES. You can find Hamilton’s group activities in this unit’s TEACHING AND GROUP ACTIVITIES download.
WT: ???
ARE: ??
GD: ???
Year 4

14. Describe your heptagon to your partner…
Day 2: Draw different polygons; identify their properties.
Describe your heptagon to your partner…
Children can now go on to do differentiated GROUP ACTIVITIES. You can find Hamilton’s group activities in this unit’s TEACHING AND GROUP ACTIVITIES download.
WT/ ARE/ GD: Play a ‘Guess the shape’ game; draw 2-D shapes based on given properties.
ARE/ GD: Identify the properties of polygons and use this to sort them.
Does it have any right angles, obtuse or acute angles or lines of symmetry?
Year 4

15. Day 2: Draw different polygons; identify their properties.
Is this a heptagon?
It has 7 straight sides BUT polygons have straight sides and are closed.
Is this a heptagon?
Discuss in pairs how you would describe this shape. What makes a good description?
Children can now go on to do differentiated GROUP ACTIVITIES. You can find Hamilton’s group activities in this unit’s TEACHING AND GROUP ACTIVITIES download.
WT/ARE/GD: Identify the properties of polygons and use this to sort them OR Draw 2-D shapes based on given properties.
Year 4

16. The Practice Sheet on this slide is suitable for most children.
Differentiated PRACTICE WORKSHEETS are available on Hamilton’s website in this unit’s PROCEDURAL FLUENCY box.
WT/ARE: Shape properties Sheet 1.
GD: Shape properties Sheet 2.
Year 4

17. Draw circles, identify and study polygons, especially triangles
Shape
Draw circles, identify and study polygons, especially triangles
Objectives
Day 3
Describe, name and sort triangles, identifying their properties.
Year 4

18. Let’s look at some triangles…
Day 3: Describe, name and sort triangles, identifying their properties.
Let’s look at some triangles…
Year 4

19. It has 2 equal sides and 1 line of symmetry
Day 3: Describe, name and sort triangles, identifying their properties.
Triangle 1 is called an isosceles triangle. The name comes from the Greek iso (same) and skelos (leg).
It has 2 equal sides and 1 line of symmetry
Triangle 2 is called an equilateral triangle. It is a regular shape as all its sides and angles are equal.
It has 3 lines of symmetry.
What is the same about Triangles 1 and 2; what is different?
Year 4

20. Triangle 3 has a right angle and
Day 3: Describe, name and sort triangles, identifying their properties.
Triangle 3 has a right angle and
2 equal sides. It is a right angled isosceles triangle.
Triangle 4 has 2 equal sides so is also an isosceles triangle. Both these triangles have
1 line of symmetry.
What is the same about Triangles 3 and 4; what is different?
Year 4

21. What do you notice about Triangle 5?
Day 3: Describe, name and sort triangles, identifying their properties.
What do you notice about Triangle 5?
Triangle 5 is neither symmetrical
nor has a right angle. Completely irregular triangles are called scalene.
On your whiteboard draw another scalene triangle.
Year 4

22. How could we sort the triangles into sets…
Day 3: Describe, name and sort triangles, identifying their properties.
How could we sort the triangles into sets…
Year 4

23. Day 3: Describe, name and sort triangles, identifying their properties.
Right Angled
No Right Angles
Year 4

24. Day 3: Describe, name and sort triangles, identifying their properties.
Not symmetrical
Symmetrical
Year 4

25. Here is some important vocabulary to use in today’s lesson…
Day 3: Describe, name and sort triangles, identifying their properties.
Here is some important vocabulary to use in today’s lesson…
Isosceles
Scalene
Equilateral
Side
Symmetrical
Corner/Vertex
Today would be a great day to use a problem-solving investigation – Egyptian Rope – as the group activity, which you can find in this unit’s IN-DEPTH INVESTIGATION box on Hamilton’s website.
Alternatively, children can now go on to do differentiated GROUP ACTIVITIES. You can find Hamilton’s group activities in this unit’s TEACHING AND GROUP ACTIVITIES download.
WT: Identify right angles and other properties in triangles; classify them (with support).
ARE: Identify right angles and other properties in triangles; classify them.
GD: Identify right angles and other properties in triangles; classify them, create class poster.
Right angle
Year 4

26. The Practice Sheet on this slide is suitable for most children.
Differentiated PRACTICE WORKSHEETS are available on Hamilton’s website in this unit’s PROCEDURAL FLUENCY box.
WT: Triangles Sheet 1.
ARE: Triangles Sheet 2.
GD: Triangles Sheet 2.
Year 4

27. Draw circles, identify and study polygons, especially triangles
Shape
Draw circles, identify and study polygons, especially triangles
Well Done! You’ve completed this unit.
Objectives
Day 1
Use a compass to draw circles to given radii.
Day 2
Draw different polygons; identify their properties.
Day 3
Describe, name and sort triangles, identifying their properties.
You can now use the Mastery: Reasoning and Problem-Solving questions to assess children’s success across this unit. Go to the next slide.
Year 4

28. Problem solving and reasoning questions
Always true, sometimes true or false?
• The circumference of a circle is the distance across the centre from one side to the other.
• The radius of a circle is half the diameter
• A circle is a special type of polygon
• A pentagon is a regular five-sided polygon
• A polygon has eight sides
Draw triangles to match each description
i. With a right angle and the shortest side is 3cm
ii. Two sides and two angles are equal
iii. No equal angles; one side twice as long as one other side
Make as many generalisations as you can about this collection of shapes:
Year 4