To calculate the area of a trapezium, divide it into a rectangle and two
triangles as shown below.

Now, piece together the triangular ends so that the trapezium is divided
into a triangle and rectangle. The base of the triangle is the
difference between the lengths of two parallel sides. That is, a – b.

Example 4

Find the area of the following trapezium.

Solution:

So, the area of the trapezium is 204 m^{2}.

Example 5

Find the area of the following trapezium.

Solution:

So, the area of the trapezium is 39 cm^{2}.

Remember:

A trapezium is a quadrilateral that has only one pair of parallel
sides.

The area of the trapezium is given by the following formula where a and b are the lengths of the parallel sides and h is the
perpendicular distance between the parallel sides.