Area & PerimeterArea & Perimeter
Primary 4 Mathematics
Area & PerimeterArea & Perimeter
2
Chapter Learning OutcomesChapter Learning Outcomes
Area and perimeter for rectangles and squares
Area and perimeter for composite figures
Area & PerimeterArea & Perimeter
Rectangles and Squares:Rectangles and Squares:Perimeter and AreaPerimeter and Area
3
This is a rectangle.We can label the sides as its length
and breadth.
Area & PerimeterArea & Perimeter
Rectangles and Squares:Rectangles and Squares:Perimeter and AreaPerimeter and Area
4
This is a square.We can label the sides as its length and breadth; all 4 sides are equal.
Area & PerimeterArea & Perimeter
Rectangles and Squares:Rectangles and Squares:Perimeter and AreaPerimeter and Area
5
The perimeter of a rectangle or square is the sum of all of its 4
sides.
Area & PerimeterArea & Perimeter
Rectangles and Squares:Rectangles and Squares:Perimeter and AreaPerimeter and Area
6
Perimeter of rectangle = Length + Length + Breadth + Breadth
Perimeter of square = 4 x Length
Area & PerimeterArea & Perimeter
Rectangles and Squares:Rectangles and Squares:Perimeter and AreaPerimeter and Area
7
The area of a rectangle or square is the product of its length and
breadth.
Area & PerimeterArea & Perimeter
Rectangles and Squares:Rectangles and Squares:Perimeter and AreaPerimeter and Area
8
Area of rectangle or square= Length x Breadth
Area & PerimeterArea & Perimeter
ExampleExample
Benji bent a length of wire around a rectangular photo frame. How long was the length of wire?
9
Length of wire = Perimeter of frame
= 16 cm + 16 cm + 9 cm + 9 cm
= 50 cm
The wire was 50 cm long.
Area & PerimeterArea & Perimeter
ExampleExample
Cherie cut out a square piece of cloth with length 12 cm. What was the area of the piece of cloth?
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Area of square = 4 x Length
= 4 x 12 cm
= 48 cm2
The piece of cloth had an area of 48 cm2.
Area & PerimeterArea & Perimeter
Composite Figures:Composite Figures:Perimeter and AreaPerimeter and Area
11
This composite figure can be broken down into a square and a rectangle.
I can break it down into two rectangles.
Area & PerimeterArea & Perimeter
ExampleExample
Find the perimeter of the figure ABCDEF.
12
BC = AF – DE = 5 cm
CD = FE – AB = 7 cm
Perimeter = 5 cm + 7 cm + 25 cm + 22 cm + 32 cm + 17 cm
= 108 cm
Area & PerimeterArea & Perimeter
ExampleExample
Find the area of the figure ABCDEF.
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BC = AF – DE = 5 cm
CD = FE – AB = 7 cm
Area = (25 cm x 5 cm) + (32 cm x 17 cm)
= 125 cm2 + 544 cm2
= 669 cm2
Area & PerimeterArea & Perimeter
ExampleExample
Craig is laying turf grass in his garden. What is the perimeter and area of the garden covered by turf grass?
14
Perimeter = 23 m + 13 m + 6 m + 6 m + 11 m + 6 m + 6 m + 13 m
= 84 m
Area & PerimeterArea & Perimeter
ExampleExample
Craig is laying turf grass in his garden. What is the perimeter and area of the garden covered by turf grass?
15
13 m – 6 m = 7 m
Area = (23 m x 6 m) + (6 m x 6 m) + (6 m x 6 m)
= 138 m2 + 36 m2 + 36 m2
= 210 m2
Area & PerimeterArea & Perimeter
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Reference - Reference - TextbooksTextbooks
Learning Outcomes
Rectangles and squares 4B Pg 98 – 104 4B Pg 100 – 104
Composite figures 4B Pg 105 – 116 4B Pg 105 – 111