Trapeziums (other)

A general trapezium is a quadrilateral with exactly one pair of parallel sides, called the bases. The other two sides are called the legs and may be of different lengths. 'Other' trapeziums refer to those that are not isosceles (legs are not equal) and do not have right angles.

Important properties

• The sum of the interior angles is 360°.

• The parallel sides are called bases; the non-parallel sides are called legs.

• The area can be found using the formula: $\text{Area} = \frac{1}{2} (b_1 + b_2) h$ where $b_1$ and $b_2$ are the lengths of the bases and $h$ is the height (the perpendicular distance between the bases).

• The diagonals usually have different lengths and do not have special properties unless the trapezium is isosceles.