# Area - Revision The area of a shape is simply defined by : “the amount of space a shape takes up.” Think of a square measuring 1 cm by 1cm we say it is.

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Area - Revision The area of a shape is simply defined by : “the amount of space a shape takes up.” Think of a square measuring 1 cm by 1cm we say it is : 1cm 1cm 2 ( 1 square centimetre )

Area of a Rectangle Example Find the area of the rectangle L = 9cm B = 2cm Area = Length x Breadth A = L x B A = 9 x 2 A = 18 cm 2

Area of a Rectangle Example Find the length B of the rectangle opposite L = 12cm B cm Area = Length x Breadth A = L x B 36 = 12 x B Balancing Method A = 36cm 2 Remember units

Calculate the area of this shape 8cm 9cm 5cm 6cm A = l x b A = 9 x 8 A = 72cm 2 A = l x b A = 6 x 5 A = 30cm 2 Total Area = = 102cm 2 72 + 30 Area of a Composite

Calculate the area of this shape 5cm 6cm 16cm 5cm A = l x b A = 16 x 5 A = 80cm 2 Rectangle 1 Rectangle 2 A = l x b A = 6 x 5 A = 30cm 2 A = 30cm 2 Total Area = 80 + 30 =110cm 2 Area of a Composite

6 Any Triangle Area h b Sometimes called the altitude h = vertical height

7 Any Triangle Area 6cm 8cm Example 1 : Find the area of the triangle.

Any Triangle Area 10cm 4cm Example 2 : Find the area of the triangle. Altitude h outside triangle this time.

Parallelogram Area b Important NOTE h = vertical height h

Example 1 : Find the area of parallelogram. 9cm 3cm

Area of a Rhombus D d This part of the rhombus is half of the small rectangle.

Area of a Kite D d Exactly the same process as the rhombus

Rhombus and Kite Area Example 1 : Find the area of the shapes. 5cm 2cm 9cm 4cm

Trapezium Area W X Y Z 1 2 a cm b cm h cm Two triangles WXY and WYZ

Trapezium Area Example 1 : Find the area of the trapezium. 6cm 4cm 5cm

Parts of the Circle Circumference O O = centre of circle The radius is measured from the centre of the circle to the edge. radius diameter The diameter is measured from one edge to the other passing through the centre of the circle. Radius = ½ x diameter Diameter = 2 x radius

Circle Investigation To calculate the circumference of a circle

Main part of a Circle 10cm 2cm Example : Find the length of the circumference (Perimeter) of each circle

Area of a Circle To find the area of a circle A = Πr² Where A = area r = radius

Area of a circle Q.Find the area of the circle ?Solution 4cm

Area of a circle Q. The diameter of the circle is 60cm. Find area of the circle?Solution

What have we learned so far Area of a Circle

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