Shape and Space - part 1
PERIMETER A
If you want to put a border around the edge of a poster or a room,
you need to find the perimeter.
To find the perimeter you add the measurements of all the sides.
Example:
4cm
3cm
3cm
4cm
The perimeter of this rectangle = 4 + 3 + 4 + 3 cm = 14cm
A)
1)
Try measuring the sides of each of these shapes in centimetres
and add them up to find the perimeter:
2)
3)
4)
5)
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6)
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Shape and Space - part 1
7)
8)
9)
10)
11)
13)
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12)
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Shape and Space - part 1
The diagrams in the next questions are not drawn to the right size.
Example:
14m
10m
11m
16m
This children’s playground is to have a fence round the outside. How
long will it be?
14 m +
11 m
16 m
10 m
51 m
Answer 51 m long
B)
Try these questions: (don’t forget you don’t need to measure).
What length of border is needed for these play areas?
1)
40m
30m
2)
45m
30m
50m
50m
40m
3)
20m
20m
60m
20m
4)
20m
118m
20m
40m
40m
20m
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121m
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Shape and Space - part 1
Sometimes the diagram may not show all the side lengths. It’s easier
if you write them on yourself.
Example:
15m
9m
The length of this hall is 15m.
The width is 9m.
Write these measurements in:
15m
Perimeter = 15m
15m
9m
9m
9m
15m
48m
C)
9m
The perimeter = 48m
Try these:
What length of wood will be needed to make frames for these
photos?
1)
40cm
2)
18cm
28cm
13cm
3)
50cm
4)
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40cm
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45cm
65cm
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Shape and Space - part 1
You could try drawing a sketch for these questions:
5)
Nathan is fixing a picture rail round a room which is 6m long
and 5m wide. What length will he have to buy?
6)
Jenny has to put a fence all round a garden which is 22m
long and 11m wide. How many metres of fencing does she
need?
7)
A cushion cover needs ribbon piping round the edge - the
cover is 30cm square. How much will be used? Is one metre
enough?
8)
A gutter runs all round a roof which is 15m long and 12m
wide. What length is the gutter?
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Check your answers then discuss with your tutor what you need to
work on next.
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Shape and Space - part 1
Answers
Perimeter A
B)
A)
C)
1)
16cm
1)
140m
1)
136cm
2)
20cm
2)
205m
2)
62cm
3)
20cm
3)
120m
3)
180cm
4)
20cm
4)
319m
4)
220cm
5)
24cm
5)
22m
6)
22cm
6)
66m
7)
20cm
7)
120cm
8)
24cm
8)
54m
9)
30cm
10) 32cm
11) 18cm
12) 16cm
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13) 20cm
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not enough
Shape and Space - part 1
PERIMETER B
Re-cap: the perimeter is the distance around the edge of a shape.
If the measurements you’re using have decimal fractions, check that
you line up the decimal points when you add. Whole numbers are best
written with a decimal point - e.g. 6cm can be written 6.0cm.
Example:
4.6cm
4.6
4.6
2.5
+ 2.5
14.2cm
2.5cm
The perimeter = 14.2cm
A)
Try measuring the sides of these printing blocks in centimetres
to find the perimeter:
a
1)
2)
m
4)
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3)
A
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M
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Shape and Space - part 1
Complex Shapes
In more complex shapes, you still need to add all the side
measurements.
 3m
Example:
3m
3m
5m
2m
6m
Make a mark  where you mean to start, so you don’t forget where
you’re up to. The perimeter = 3 + 5 + 6 + 2 + 3 + 3 m
= 22 m
B)
Try finding the perimeters of these shapes:
The diagrams are not drawn to the right size.
1)
4cm
2)
2cm
10m
3m
3cm
5cm
3cm
7m
8m
7cm
5m
3m
2mm
12in
3)
4)
10mm
10mm
4in
10in
6mm
3mm
4mm
7in
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7in
4mm
11mm
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10in
3in
8
5in
Shape and Space - part 1
Sometimes you may need to work the measurements out for yourself in
complex shapes.
Example:
To find the perimeter of this room, you also need to know what side
is.
s
15m
6m
10m
s
4m
8m
But the whole of the bottom edge must be 15m, the same as the top.
15m
6m
10m
s=7
4m
8m
15m
So side
s must be 7m (15 - 8)
The perimeter = 15 + 10 + 8 + 4 + 7 + 6 m
= 50 m
C)
Try these questions:
Find the perimeter of these rooms to see what length of carpet
gripper is needed:
Make sure you write the length on all the sides.
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(see over)
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Shape and Space - part 1
1)
2)
10m
8m
6m
12m
5m

2m

4m

2m

2m
2m
5m
3)
4)
4m
10m
4m
6m
5m
12m
2m
2m
5)
4m
6)
4.8m
4m
3m
6.5m
4m
2m
7.2m
4m
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Check your answers then discuss with your tutor what you need
to work on next.
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Shape and Space - part 1
Answers
Perimeter B
A)
C)
B)
17.8 cm
1)
24 cm
1)
44 m
2)
18.8 cm
2)
36 m
2)
26m
3)
19.8 cm
3)
50 mm
3)
18 m
4)
24 cm or 24.0 cm
4)
58 in
4)
56 m
5)
17.6 m
6)
27.4 m
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1)
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