# how to find perimeter

Document Sample

```					A Resource for Free-standing Mathematics Qualifications                                Perimeter and Area

Information Sheet
Perimeter
5m
The perimeter of a shape is the total length of its sides.

3m
The perimeter of this rectangular lawn = 5 + 3 + 5 + 3 = 16 m

Perimeter of a rectangle            P=l+w+l+w                   where l is the length and w the width

This can also be written as         P = 2l + 2w       or        P = 2(l + w)

Area
Area measures the surface of something, usually in square metres (m2 ), square centimetres
(cm2 ) or square millimetres (mm2 ).
5m
The area of the lawn is 15 m2
Each square has
3m             an area of 1 m2

Area of a rectangle = length × width

This can be written as              A = lw            where l is the length and w the width

Sometimes you can split shapes into two or more rectangles.

Example

The perimeter of this L-shaped floor                                     3m
= 3 + 1.5 + 2.2 + 3 + 5.2 + 4.5 = 19.4 m
1.5 m
The area is split into two rectangles, A and B.
4.5 m        A               2.2 m
Area of A = 4.5 × 3 = 13.5 m    2
3m
B
Area of B = 3 × 2.2 = 6.6 m2

Total area = 13.5 + 6.6 = 20.1 m2                                              5.2 m

Photo-copiable
The Nuffield Foundation                           1

Worksheet

1    Each diagram below shows the dimensions of the floor in a room.
Find the perimeter and area of each floor.

b)         4.5 m              c)               6.4 m
a)          6m

4m                                    5m                           4.8 m

2    Find the perimeter and the area of each towel and the facecloth.
50 cm
140 cm
30 cm
Bath                                                   26 cm
70 cm                                        100 cm       Hand
Towel
Towel
Facecloth

3 Find the perimeter and area of this £5 note.                                            70 mm

135 mm

4 Calculate the perimeter and area of each field shown below.
a)                               b)                                c)

34 m                             260 m                                        62.5 m

290 m                                    96.2 m
25 m

Photo-copiable
The Nuffield Foundation                         2

5 Find the perimeter and area of the floor of each room in the diagrams below.

a)                                                              6m
b)
2m                                                                                7m
6m
3m                                           10 m
6m

4m

c)                                                  d)                 5.2 m

3.5 m                                                                          2.1 m
2m

4m                                                                             2.5 m

1.5 m                                                                 1.2 m
1.5 m
5m

6 Find the perimeter and area of each shape.

a)               44 cm                                    b)           38 mm

22 cm                                             16 mm

44 cm
14 mm
24 mm

c)
22 cm                                                               38 mm
75 mm
75 mm

75 mm
125 mm

75 mm
Photo-copiable
The Nuffield Foundation                         3

Teacher Notes

Unit    Foundation Level, Working in 2 and 3 dimensions

Notes
Page 1 is an information sheet that shows how to find the perimeter and area of rectangles and
shapes made from rectangles. The first worksheet (Page 2) requires students to find the perimeter
and area of single rectangles, whereas the second worksheet (Page 3) contains composite shapes.
An accompanying Powerpoint presentation with the same name can be used as an introduction to
this work.

1   a) Perimeter = 20 m, Area = 24 m2                   b) Perimeter = 19 m,   Area = 22.5 m2
c) Perimeter = 22.4 m, Area = 30.72 m2

2   Bath Towel: Perimeter = 420 cm,           Area = 9800 cm2
Hand Towel: Perimeter = 300 cm,           Area = 5000 cm2
Facecloth:  Perimeter = 112 cm,           Area = 780 cm2

3   Perimeter = 410 mm,       Area = 9450 mm2

4   a) Perimeter = 118 m, Area = 850 m2                 b) Perimeter = 1100 m, Area = 75 400 m2
c) Perimeter = 317.4 m, Area = 6012.5 m2

5   a) Perimeter = 26 m,      Area = 30 m2              b) Perimeter = 46 m,   Area = 102 m2
c) Perimeter = 32 m,      Area = 53 m2              d) Perimeter = 25 m,   Area = 28.72 m2

6   a) Perimeter = 176 cm, Area = 1452 cm2              b) Perimeter = 184 mm, Area = 1520 mm2
c) Perimeter = 850 mm,Area = 26 250 mm2

Photo-copiable
The Nuffield Foundation                         4

```
DOCUMENT INFO
Shared By:
Categories:
Stats:
 views: 535 posted: 2/24/2010 language: English pages: 4
Description: Guide teaches you how to find perimeter
How are you planning on using Docstoc?