Lesson -Area-Area of parrallelogram-ppt

Area explanation

1. Area of a Parallelogram and Trapezium
Starter:
Find the area of these triangles
4cm
6cm
5cm
8cm
1cm
7cm
12cm
2
20cm
2
3.5cm
2

2. Area of a Parallelogram and Trapezium
Definitions:
Area: the amount of space inside a 2D shape
(cm
2
/m
2
)

3. Area of a Parallelogram and Trapezium
Investigation:
What is the area of this rectangle?
4cm
6cm

4. Area of a Parallelogram and Trapezium
Investigation:
Cut the shape like this
4cm
6cm

5. Area of a Parallelogram and Trapezium
Investigation:
What is the area of this rectangle?

6. Area of a Parallelogram and Trapezium
Investigation:
Cut the shape like this

7. Area of a Parallelogram and Trapezium
Investigation:
What is the area of this parallelogram
4cm
6cm

8. Area of a Parallelogram and Trapezium
Formula:
The formula for the area of a parallelogram is:
Height (h)
Base (b)
hbArea

9. Area of a Parallelogram and Trapezium
Example:
Find the area of this parallelogram
5cm
4cm
hbArea
45Area
2
20cmArea

10. Activity 1:
Find the area of the following parallelograms1
Find the missing lengths of these parallelograms when given the area2
Find the area of this shape3
a b c d
a b c d
5cm
3cm
7mm
7mm
8m
5m
4.5cm
3cm
6cm
a 24cm
2
b
5cm 35cm
2
c
10cm
46cm
2 d
4.5mm
18mm
2
10cm
8cm
5cm
6cm
4cm
Below illustrates a garden which needs to be
seeded with grass. The grass seeds costs
£8.50 per packet and covers 15m
2
.
Work out the cost to cover the garden with
grass seeds.
8m
5m
15cm
2
49mm
2
40m
2
13.5cm
2
4cm 7cm
4.6cm 4mm
41cm
2
40m
2
3 packs
£25.50