kungfu math p4 slide18 (area)pdf
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• concepts of area and perimeter of a plane figure
• measurement of area in square units
• measurement of area in square centimetres
What will we learn today?
Measurement Area
What is Area?
Area is the size of a surface.
Area of Simple Shapes
There are special formulas for certain shapes:
For example:
What is the area of this rectangle?
5cm
3cm
Area of Simple Shapes
There are special formulas for certain shapes:
For example:
What is the area of this rectangle?
Area = Length x Breadth
5cm
3cm
Area of Simple Shapes What is the area of this rectangle?
Area = Length x Breadth
Length is the longest dimension of an object.
5cm
3cm
Length
Area of Simple Shapes What is the area of this rectangle?
Area = Length x Breadth
Breadth is the extent or measure of how broad or wide something is.
5cm
3cm Breadth
Area of Simple Shapes What is the area of this rectangle?
Area = Length x Breadth
Length is the longest dimension of an object.
Breadth is the extent or measure of how broad or wide something is.
5cm
3cm
Length
Breadth
Area of Simple Shapes
Therefore, by applying the formula.
What is the area of this rectangle?
Area of rectangle = Length x Breadth
5cm
3cm
Area of Simple Shapes
Therefore, by applying the formula.
What is the area of this rectangle?
Area of rectangle = Length x Breadth
= 5cm x 3cm
5cm
3cm
Area of Simple Shapes
Therefore, by applying the formula.
What is the area of this rectangle?
Area of rectangle = Length x Breadth
= 5cm x 3cm
= 15 cm²
5cm
3cm
Area of Simple Shapes
Therefore, by applying the formula.
What is the area of this rectangle?
Area of rectangle = Length x Breadth
= 5cm x 3cm
= 15 cm²
5cm
3cm
Notice the difference in units?
Area of Simple Shapes
Therefore, by applying the formula.
What is the area of this rectangle?
Area of rectangle = Length x Breadth
= 5cm x 3cm
= 15 cm²
The unit for AREA is cm² or m²
Summary
You can only find area when the length and breadth have the same units.
For example,
the length is 5 cm and the breadth is 4 cm.
The area will be 20 cm².
Summary
You can only find area when the length and breadth have the same units.
For example,
the length is 5 m and the breadth is 4 m.
The area will be 20m².
The area of Square T is 45cm² smaller than the area of Square P.
Find the edge of Square Q.
P Q
Area = 81cm²
The area of Square T is 45cm² smaller than the area of Square P.
Find the edge of Square Q.
P Q
81 – 45 = 36 cm²
Area = 81cm²
The area of Square T is 45cm² smaller than the area of Square P.
Find the edge of Square Q.
P Q
6 x 6 = 36 cm²
Area = 81cm²
6cm
6cm
The area of Square T is 45cm² smaller than the area of Square P.
Find the edge of Square Q.
P Q
The edge of Square Q is 6cm.
Area = 81cm²
6cm
6cm
The perimeter of a rectangular plot of land is 32m. Its length is 9m. Find its area.
Step 1: Find the breadth.
Area = ? cm²
9m
?m
The perimeter of a rectangular plot of land is 32m. Its length is 9m. Find its area.
Step 1: Find the breadth. 32 - 9 – 9 = 14 m
14 ÷ 2 = 7 m
Area = ? cm²
9m
?m
The perimeter of a rectangular plot of land is 32m. Its length is 9m. Find its area.
Step 2: Find the area. 9 x 7 = 63m²
Area = ? cm²
9m
7m
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