Nuffield Free-Standing Mathematics Activity Geometrical design
© Nuffield Foundation 2011 Free-Standing Mathematics Activity Perimeter and area.
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© Nuffield Foundation 2011 Free-Standing Mathematics Activity Perimet er and area
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Transcript of © Nuffield Foundation 2011 Free-Standing Mathematics Activity Perimeter and area.
© Nuffield Foundation 2011
Free-Standing Mathematics Activity
Perimeter and area
© Nuffield Foundation 2011
The gardener needs to work out the perimeter and the area of the lawn
How much edging do I need to go around
the lawn?
How much lawn feed do I need?
© Nuffield Foundation 2011
Perimeter of a rectanglelength
width
length
width= length + width
+ length + width
Think aboutIs there another way to find the perimeter?
Think aboutIs there another way to find the perimeter?
lawn
5 m
3 m= 5 + 3 + 5 + 3 Perimeter of this lawn
= 16 m
The perimeter of a shape is the total length of its sides
© Nuffield Foundation 2011
Area
Area measures the surface of something
1 metre
1 metre
1 square metre
1 m2
1 cm
1 cm 1 cm2
1 mm
1 mm 1 mm2
© Nuffield Foundation 2011
Area of a rectangular lawn
15 square metres The area is
5 metres long
3 metres wide
Area of a rectangle = length × width
= 15 m2
© Nuffield Foundation 2011
page
21 cm
30 cm= 30 × 21 Area of the page
= 630
65 m
32 m= 65 × 32 Area of field
= 2080
cm2
Area of rectangle = length × width
m2 field
© Nuffield Foundation 2011
5.2 m
4.5 m
3 m
3 m
1.5 m
2.2 m
To find the perimeter of this L-shaped room
Perimeter
3 + 1.5 + 2.2 + 3+ 5.2 + 4.5 = 19.4 m
Think aboutWhat else is needed?
Think aboutWhat else is needed?
© Nuffield Foundation 2011
5.2 m
4.5 m
3 m
3 m
1.5 m
2.2 mA
B
Area of A = 4.5 × 3= 13.5 m2
Area of B = 3 × 2.2= 6.6 m2
Total area = 13.5 + 6.6 = 20.1 m2
Think aboutHow can we do this?
Think aboutHow can we do this?
To find the area of this L-shaped room
© Nuffield Foundation 2011
5.2 m
4.5 m
3 m
3 m
1.5 m
2.2 m
A
B
Another way
Area of A = 3 × 1.5
= 4.5 m2
Area of B = 5.2 × 3
= 15.6 m2
Total area = 4.5 + 15.6 = 20.1 m2
To find the area of this L-shaped room
© Nuffield Foundation 2011
5.2 m
4.5 m
3 m
3 m
1.5 m
2.2 m
Yet another way!
Area of large rectangle = 5.2 × 4.5
= 23.4 m2
Area of small rectangle = 2.2 × 1.5
= 3.3 m2
Total area =23.4 − 3.3 = 20.1 m2
Think aboutWhich way was best?
Think aboutWhich way was best?
To find the area of this L-shaped room
© Nuffield Foundation 2011
• What does the word ‘perimeter’ mean?
At the end of the activity
• How do you find the perimeter of a shape?• What units are used for perimeters?• How do you find the area of a shape?• What units are used for areas?
• How would you find the area of this shape?
Car parkPlay area Carpet Mirror
surround
