Page 173 - Mathematics Coursebook

18.2 Calculating the area and perimeter of rectangles

) Exercise 18.2

1 Work out the area and perimeter of each of these rectangles.
2 cm
5 mm
4 m
a 2 cm b 4 m 4 m c5 mm
2 cm
5 mm
2 cm
2 cm2 cm 4 m 4 m 5 mm
5 mm
5 mm
4 m
4 cm
8 mm
4 cm 8 mm
4 cm
8 mm
5 m
4 cm4 cm 5 m 5 m 8 mm
4 cm
8 mm
8 mm
5 m
5
5 mm
d e f
3 mm
3 mm
5 cm 7 m 3 mm
5 cm 7 m 7 m 3 mm
5 cm
3 mm
3 mm
7 m
5 cm5 cm 7 m 7 m 12 mm
5 cm
12 mm
12 mm
12 mm
12 mm
12 mm
5 cm
8 m
2 A sheet of A5 paper is 210 mm long and 148 mm wide.
8 m
5 cm
8 m
5 cm
8 m
5 cm5 cm
5 cm
What is the area of a sheet of A5 paper? 8 m 8 m
3 Connor is laying a new patio in his garden. 4 m
The diagram shows the dimensions of his patio.
Work out:
a the area of the patio b the perimeter of the patio. 2.5 m
2
4 A rectangular room has an area of 12 m .
The length of the room is 4 m.
Work out:
a the width of the room b the perimeter of the room.

5 Copy and complete both methods shown to find the area of this rectangle.
Method 1 Method 2 3 mm
Width = 3 mm = 0.3 cm Length = 2 cm = 20 mm
Area = 2 × 0.3 = cm Area = 20 × 3 = mm 2 2 cm
2
6 The table shows some information about five rectangles A to E.

Rectangle Length Width Area Perimeter
A 8 mm 6 mm
B 4 cm 28 cm 2
C 12 m 60 m 2
D 8 cm 22 cm
E 1.5 mm 20 mm
Copy and complete the table.
7 Keira wants new carpet in her hall.
The hall is a rectangle that measures 4 m long by 90 cm wide.
Work out the area of carpet that she needs.
8 Oditi and Tanesha are drawing rectangles with whole-number lengths and widths.
Who is correct? Explain your answer.
I can only draw three different There are four different rectangles
2
rectangles with an area of 24 cm . with an area of 24 cm .
2
172 18 Area, perimeter and volume