1. Simple Areas Area of a rectangle Area of a right-angled triangle
Area of composite shapes

2. Starter Questions
34o

3. Area of a Rectangle www.mathsrevision.com Learning Intention
Success Criteria
1. To come up with a formula
for the area of a
rectangle.
To be able to state area formula for a rectangle.
Apply formula correctly.
(showing working)
Use the formula to solve problems.
Answer containing
appropriate units

4. General Jack’s Carpets
Problem…
General Jack’s Carpets
How much for this one? ?
Only £5 a square metre!

5. How much for 18 square metres?
Problem… 1m 1m
= 1 square metre
6 m
6 square metres
3 m
6 square metres
6 square metres
3 rows of 6 squares
= 3 x 6
= 18 square metres
18 x £5 = £90
How much for 18 square metres?

6. 6 3 Area of a rectangle 6 x 3 = 18 m² Area = length x breadth 6
x 3
= 18 m²
Area =
length
x breadth

7. Example 1 11 cm 6 cm Area = length x breadth A = l x b A = 11 x 6
A = 66 cm²
Find the area of
the rectangle

8. Example 2 12 cm Area = length x breadth A = l x b A = 12 x 12
A = 144 cm²
12 cm
Find the area of
the square

9. Starter Questions
123o

10. Area of A Right-Angled Triangle
Learning Intention
Success Criteria
1. Use the area of a rectangle formula to help us to come up with a formula to calculate the area of any right-angled triangle.
Know area of a right-angled triangle formula
2. Use formula to work out area of triangle.
3. Show all working and units.

11. right-angled triangle
Area of a
right-angled triangle
4 cm
7 cm
Area of rectangle
= l x b
= 7 x 4
= 28 cm²
Area of triangle
= ½ x Area of rectangle
= ½ x 28
= 14 cm²

12. Area of triangle Short cut
4 cm
height
base
7 cm
Area of triangle
= ½ x 7 x 4
= ½ x 28
= 14 cm²
Area Δ =
x base
x height

13. Example 1 10 cm 15 cm Area Δ=½ x base x height AΔ =½ x b x h
AΔ = ½ x 15 x 10
10 cm
AΔ = 75 cm²
15 cm
Find the area of
the triangle

14. Example 2 8 cm 12 cm Area Δ=½ x base x height AΔ =½ x b x h
AΔ = ½ x 8 x 12
12 cm
AΔ = 48 cm²
Find the area of
the triangle

15. right-angled triangle
Area of a
right-angled triangle
Now try worksheet
Exercise 1

16. Starter Questions
34o

17. Area of a Composite www.mathsrevision.com Made up of Simple shapes
Learning Intention
Success Criteria
1. To use knowledge to find area of more complicate shapes.
To be able to use knowledge gained so far to find the area of more complicated shapes..
Show appropriate working.

18. Composite shapes
10 cm
6 cm ? ?
3 cm
13 cm

19. Composite shapes www.mathsrevision.com Area (1) = l x b = 10 x 6
10 cm
6 cm
(1)
6 cm ?
(2)
3 cm
Area (1)
= l x b
= 10 x 6
= 60 cm²
Area (2)
= ½ x b x h
= ½ x 3 x 6
= 9 cm²
Area of shape
= (1) + (2) =
= 69 cm²

20. Example 1 Area (1)= l x b =15 x 8 = 120 cm² Area (2) = l x b =9 x 3?
8cm
(1)
Area (2) = l x b
=9 x 3
= 27 cm²
(2)
Area of shape =
(1) + (2) = ?
9cm
= 147 cm²
Find the area of
the shape

21. Example 2 Area (1)= l x b =20 x 12 = 240 cm² Area (2) = l x b =10 x 6
Area of shape =
(1) – (2) =
(1)
= 180 cm²
Find the area of
the shape

22. Now try worksheet Exercise 2
Composite shapes
Now try worksheet Exercise 2