Trapezoid
A trapezoid (in North America) or trapezium (in Britain and elsewhere) is a quadrilateral, which is defined as a shape with four sides, which has one set of parallel sides. In North America, they call a trapezium as an irregular quadrilateral by people outside of North America.
Calculating area
To calculate the area of a trapezoid, you must add the two parallel sides together, divide that by 2, then times that by its height.
- [math]\displaystyle{ A = \frac{a + b}{2} \cdot h }[/math]
Other websites
- "Trapezoid" on MathWorld
- Trapezoid definition Area of a trapezoid Median of a trapezoid With interactive animations
- Trapezoid (North America) at elsy.at: Animated course (construction, circumference, area)