How do you find the area of a trapezium?

To find the area of a trapezium, use the formula: \(\frac{1}{2} \times (a + b) \times h\).

A trapezium is a four-sided shape with at least one pair of parallel sides. These parallel sides are called the bases, and the other two sides are the non-parallel sides. In the formula, \(a\) and \(b\) represent the lengths of the two parallel sides, and \(h\) is the perpendicular height (the distance between the parallel sides).

To use the formula, first measure the lengths of the two parallel sides. Let's call these lengths \(a\) and \(b\). Next, measure the perpendicular height \(h\). This is the shortest distance between the two parallel sides, not the length of the non-parallel sides.

Once you have these measurements, add the lengths of the parallel sides together: \(a + b\). Then, multiply this sum by the height \(h\). Finally, divide the result by 2 to get the area of the trapezium. So, the area \(A\) can be calculated as:
\[ A = \frac{1}{2} \times (a + b) \times h \]

For example, if the lengths of the parallel sides are 8 cm and 5 cm, and the height is 4 cm, the area would be:
\[ A = \frac{1}{2} \times (8 + 5) \times 4 = \frac{1}{2} \times 13 \times 4 = 26 \text{ cm}^2 \]

This formula works for any trapezium, regardless of the lengths of the non-parallel sides.