Page 232 - SK Year 5 Mathematics DLP

AREA OF COMPOSITE SHAPES

1 Calculate the area of the composite shape coloured by Chin.

Write down the
4 units measurement of its
length, breadth,
4 units A B base, and height.

2 units
4 units

Area of the square, A:
4 units × 4 units = 16 units 2

Area of the right-angled triangle, B:
Area of a square 1 1
= length × breadth 2 × 2 units × 4 units = 4 units 2
1
Area of a triangle
2
2
1 Area of the composite shape = 16 units + 4 units
= × base × height
2 = 20 units 2
The area of the composite shape coloured by Chin is 20 units .
2

2 2 m
What is the area of the painted wall?

3 m The area of the painted wall

= surface A + surface B
A
= (3 m × 2 m) + (3 m × 5 m)

2
= 6 m + 15 m 2
3 m B = 21 m 2

2
The area of the painted wall is 21 m .
5 m

• Discuss the role of the inner sides of the composite shape to calculate
224 the area of the composite shape.
6.3.2
• Carry out group activities to calculate areas based on two given
composite shapes. Each group presents their work.