This week we will be looking at Perimeter and Area

Lesson 1 Finding the perimeter of a shape Equipment: pen/pencil, paper or whiteboard and marker

Perimeter The perimeter is the distance around the outside of a shape. An easy way to remember is to imagine you are taking a walk around the shape. Add each length as you go: We need to add the measurements of the sides together to calculate the perimeter. So the perimeter of this rectangle is: 5cm + 3cm + 5cm + 3cm = 16cm Activity 1

1. Calculate the perimeter of this shape if each square equals 1cm.

Perimeter ………cm + ……cm + ……cm + ….…cm =………..cm It doesn’t matter how many sides the shape has, we still need to add them together to get the perimeter.

2. Try this one:- (If you count how many sides there are first, you will be sure you do not miss one when you are adding)

Perimeter: ...…cm + ……cm + ..…cm + ……cm + …..cm + ..…cm + …...cm + .…..cm = …..cm

Activity 2: Calculate the perimeter of these shapes

Task 1.

Task 2.

Task 3

Lesson 2 Using Perimeter to solve problems Being able to measure a Perimeter can help to solve practical problems. If you want to decorate a picture frame with ribbon, how do you know how much you will need? We can work out the perimeter to tell us how much ribbon we will need. 24cm

12cm If the frame is 24 cm on 2 sides and 12cm on the other 2 sides, the perimeter will be

24cm + 24cm + 12cm + 12cm = 72 cm So you would need 72cm of ribbon to decorate the picture frame. Activity 1 Try to work out the perimeter in these questions.

Answer ………………………………….m

Answer ………………………………….m

Answer ………………………………….cm

Answer ………………………………m

Answer …………………………………cm.

Answer ………………………………….cm Bonus Question: Can you convert the answer to metres? ………….m

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16

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76

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23

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90

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48

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Lesson 3 Calculating the area of a shape We have been looking at Perimeter, which is the measurement of the OUTSIDE of a shape

Now we want to look at the AREA of the shape, which is the INSIDE of the shape, it is measured in cm2. In this diagram each square on the grid measures 1 cm wide, by 1 cm deep, this is 1cm2

The yellow shape is made up of 7 squares, each one is 1 cm2.

so the total area is = 7 cm2

The yellow shape would fit into the green rectangle 4 more times, so will fit in 5 times. So we could say that we have 7 lots of 5, or 7 x 5 = 35 cm2

The area of yellow rectangle How many times it fits into the green rectangle We can check our answer by counting the squares, There are 35 squares, each one 1cm2 , so the AREA is 35 cm2

Activity 1: Work out the Area of this shape. See how many squares are in a row, then how many rows there are. Times the 2 numbers together to get the total. Count the squares to check your answer. ……………. X ………………… = ………..cm2

Activity 2 Equipment: paper pen/pencil or whiteboard and marker Work out the area of these shapes

Lesson 3 Answers:

Activity 1: 30cm2

Activity 2:

1. 8cm2 2. 9cm2 3. 10cm2 4. 6cm2 5. 6cm2 6. 8cm2 7. 16cm2 8. 7cm2 9. 4cm2 10. 4cm2 11. 15cm2 12. 12cm2 13. 18cm2 14. 25cm2 15. 2cm2 16. 24cm2 17. 15cm2 18. 16cm2 19. 9cm2 20. 36cm2 21. d c b a 22. c b a d

Lesson 4

Equipment: pen/pencil, paper or whiteboard and marker

Now we are going to look at calculating area for irregular shapes. If a shape has irregular sides or shape, finding the area can be difficult. Counting squares can be a simple method to use. How many squares make this S shape? There are 11 squares, each square is 1cm2

Area = 11 cm2 Activity 1 Count the squares to find the area of these shapes, each square = 1cm2

Activity 2 Area of Compound Shapes Try to calculate the area by dividing the shape into 2 smaller shapes.

Area of Compound Shapes Answers

A 32 cm2 B 38cm

2 C 35cm

2 D 38cm

2

E 24 cm2

F 38cm2 G 75cm

2 H 51cm

2

Lesson 5

Let’s practise area and perimeter, you will need to workout perimeter and area for these shapes using a grid.