Area

Area is the measure of the 2D space covered by the shape.

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To calculate the area of the shape above, we have to do 2\times 3={ 6 }cm^{ 2 }. (The 2 power has to always be present once the area is calculated.)

The general formula of working out the area of a rectangle/square is

Length\quad \times \quad width

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Working backwards, let’s find the length of the rectangle above.

Since we know the area and width, we have to do 56\div 7=8cm

Finding the area of triangles is slightly different.

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This is the formula for area of a triangle.

Let’s try an example:

In the formula, b = base and h = height.

So, in this example, b = 8cm and h = 5cm

\frac { 1 }{ 2 } \times 8\times 5=20cm

Just as with the perimeter, you have to know how to find the area of compound shapes (irregular shapes). The best thing to do is divide the shape into smaller shapes which you are familiar with.

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Above is a compound shape. We can divide it up into 3 rectangles.

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Then, find the area of each of the rectangles separately and then add all the values up to find the total area.

16+16+48=80{ cm }^{ 2 }

There are two other shapes that you need to know how to work out the areas for: parallelograms and trapeziums.

Parallelograms:

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This is a parallelogram, which also shows the formula to work out the area. Base x perpendicular height. Be careful, it is not base \times sloping height.

Trapeziums:

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This is a trapezium and also shows the formula to work out its area.

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