Area

Year 10 Interactive Maths - Second Edition

Area is the size of the region enclosed within a plane figure. To the carpenter or carpet layer, who is concerned with the amount of material to be used, measurement of area is very important. Area is measured in square units. The most frequently used units of area are mm², cm² and m². Land areas are often given in hectares (ha). 1 ha = 10 000 m² Areas of the following figures are often required to solve real world problems.



Area of a Square Recall that:
A square with sides of length s units has an area of A square units given by the formula
Example 13 Find the area of a square flower bed of side 7.2 m. Solution:

Note: To find the area of a region enclosed within a plane figure, draw a diagram and write an appropriate formula. Then substitute the given values and use a calculator, if necessary, to obtain the required area.

Area of a Rectangle Recall that:
A rectangle with length l units and width w units has an area of A square units given by the formula
Example 14 Find the area of a rectangular field 45 m long and 38 m wide. Solution:

Area of a Triangle Recall that:
A triangle with base b units and height h units has an area of A square units given by the formula
Example 15 Find the area of a triangle with base 19 cm and height 13 cm. Solution:

Key Terms area, square units, hectares, area formulas