To calculate the area of a trapezium, you can use the formula:

A trapezium, also known as a trapezoid in some regions, is a four-sided polygon (quadrilateral) characterized by having at least one pair of parallel sides. These parallel sides are referred to as the bases of the trapezium, while the other two sides are the non-parallel sides. In the formula, $a$ and $b$ denote the lengths of the two parallel sides, and $h$ represents the perpendicular height, which is the shortest distance between the parallel sides.

To apply the formula, begin by measuring the lengths of the two parallel sides—denote these lengths as $a$ and $b$. Then, measure the perpendicular height $h$. It’s important to note that $h$ is not the length of the non-parallel sides but rather the vertical distance between the bases.

Once you have obtained these measurements, follow these steps:

1. Add the lengths of the parallel sides together: $a + b$.
2. Multiply this sum by the height $h$.
3. Finally, divide the result by 2 to find the area of the trapezium.

Thus, the area $A$ can be expressed as:

For instance, if the lengths of the parallel sides are $8 \, \text{cm}$ and $5 \, \text{cm}$, and the height is $4 \, \text{cm}$, you can calculate the area as follows:

This formula is applicable to any trapezium, irrespective of the lengths of the non-parallel sides.