Perimeter/Area/Volume Learners will be able to: 1.Describe the terms perimeter, circumference, area and volume 2.Calculate perimeter, circumference, area and volume

Perimeter/Circumference The perimeter of a shape is the total length of its boundary. For a rectangle the perimeter is P = 2(l+w), where l is the length and w is the width.

Perimeter/Circumference The perimeter of a circle is called the circumference. The circumference, C, of a circle can be written in two ways: C = πd where d = diameter C = 2πr where r = radius

π/Pi π is a special number, equal to the ratio of the circumference of a circle to its diameter. π is an irrational number, which means it cannot be written as a fraction. π is approximately equal to The π key on your calculator gives π to more places of decimals

Example 1 A circular pond, 3.6 metres in diameter, has a fence around it, at a constant distance of 0.6 metres from the edge. Find the length of the fence.

Area Area of a shape is a measure of the amount of space it covers. For a rectangle/square the area is l x w For a circle the area, A, is given by the formula: A = πr ², where ‘r’ is radius. Diameter of a board is 45 cms. What is the area of the board? (Use BIDMAS rule) Answer: 1590 m²

Example

Volume The volume of a 3-D shape is a measure of the amount of space it occupies. The volume of a cuboid is l × w × h where l = length, w = width and h = height.

Volume The volume, V, of a cylinder is: V = πr2h where r is the base radius and h is the height.

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3-D Problems

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