2. Aim
I can calculate the area of a triangle and a parallelogram.
Success Criteria
I know the formula for calculating the area of triangles and parallelograms.
I can understand why these formulas give the area of triangles and parallelograms.
I can use the formulae to calculate the area of triangles and parallelograms.

3. The Area of a Triangle
The area of a triangle is based on being half the area of a rectangle.

4. The Area of a Triangle
The area of a triangle is based on being half the area of a rectangle.

5. Calculate the Area of a Triangle
Area of a triangle = half the area of the rectangle
= half of the base x height
height
base

6. Calculate the Area of a Triangle
Area of a triangle = half the area of the rectangle
= half of the base x height
height
base

7. Calculate the area of this triangle.
5cm
10cm
Area = × 10cm × 5cm = 1
25cm² 2

8. Calculate the area of this triangle.
7cm
8cm
Area = × 8cm × 7cm = 1
28cm² 2

9. Calculate the area of this triangle.
6cm
12cm
Area = × 12cm × 6cm = 1
36cm² 2

10. Calculate the area of this triangle.
3cm
15cm
Area = × 15cm × 3cm = 1
22.5cm² 2

11. Calculate the area of this triangle.
12cm
18cm
Area = × 18cm × 12cm = 1
108cm² 2

12. Calculate the area of this triangle.
6cm
10cm
Area = × 10cm × 6cm = 1
30cm² 2

13. Calculate the area of this triangle.
4cm
9cm
Area = × 9cm × 4cm = 1
18cm² 2

14. Calculate the area of this triangle.
8cm
11cm
Area = × 11cm × 8cm = 1
44cm² 2

15. Calculate the area of this triangle.
7cm
16cm
Area = × 16cm × 7cm = 1
56cm² 2

16. Calculate the area of this triangle.
9cm
21cm
Area = × 21cm × 9cm = 1
94.5cm² 2

17. Calculate the area of this triangle.
6cm
8cm
Area = × 8cm × 6cm = 1
24cm² 2

18. Calculate the area of this triangle.
7cm
12cm
Area = × 12cm × 7cm = 1
42cm² 2

19. Calculate the area of this triangle.
9cm
10cm
Area = × 10cm × 9cm = 1
45cm² 2

20. Calculate the area of this triangle.
11cm
13cm
Area = × 13cm × 11cm = 1
71.5cm² 2

21. Calculate the area of this triangle.
12cm
25cm
Area = × 25cm × 12cm = 1
150cm² 2

22. Calculate the height of this triangle.
Area = 14cm²
7cm
Height = 2 × = 14
4cm 7

23. Calculate the base of this triangle.
5cm
Area = 20cm²
Base = 2 × = 20
8cm 5

24. Calculate the height of this triangle.
Area = 27cm²
9cm
Height = 2 × = 27
6cm 9

25. Calculate the height of this triangle.
Area = 60cm²
12cm
Height = 2 × = 60
10cm 12

26. Calculate the base of this triangle.
7cm
Area = 52.5cm²
Base = 2 × =
52.5
15cm 7

27. The Area of a Parallelogram
The area of a parallelogram is based upon the area of a rectangle that can be made by cutting off one end
and moving it to make the rectangle.

28. Calculate the Area of a Parallelogram
Area of a parallelogram = the area of the rectangle
= base x height
height
base

29. Calculate the area of this parallelogram.
10cm
12cm
Area = 12cm × 10cm =
120cm²

30. Calculate the area of this parallelogram.
7cm
14cm
Area = 14cm × 7cm =
98cm²

31. Calculate the area of this parallelogram.
8cm
15cm
Area = 15cm × 8cm =
120cm²

32. Calculate the area of this parallelogram.
6cm
20cm
Area = 20cm × 6cm =
120cm²

33. Calculate the area of this parallelogram.
8cm
25cm
Area = 25cm × 8cm =
200cm²

34. Calculate the base of this parallelogram.
6cm
Area = 42cm²
Base = = 42
7cm 6

35. Calculate the height of this parallelogram.
Area = 40cm²
8cm
Height = = 40
5cm 8

36. Calculate the base of this parallelogram.
8cm
Area = 112cm²
Base = =
112
14cm 8

37. Calculate the base of this parallelogram.
3cm
Area = 48cm²
Base = = 48
16cm 3

38. Calculate the height of this parallelogram.
Area = 300cm²
20cm
Height = =
300
15cm 20

39. Aim
I can calculate the area of a triangle and a parallelogram.
Success Criteria
I know the formula for calculating the area of triangles and parallelograms.
I can understand why these formulas give the area of triangles and parallelograms.
I can use the formulae to calculate the area of triangles and parallelograms.