Trapezoid (C)

A trapezoid is a quadrilateral with one and only one pair of parallel sides. The distance between the paralles sides is called the altitude of the trapezoid, and the parallel sides are called the ${\bf bases}$. If the altitude of a trapezoid has length h and the bases have lengths B and b then the area of the trapezoid is

$${\rm Area} = \frac{1}{2}(b+B)h.$$

If the non-parallel sides have equal length, the trapezoid is called an isosceles trapezoid.

Exercises

1.

A trapezoid has bases of length 2 and 4 and altitude 6. What is its area?

2.

The altitude of a trapezoid is equal to the length of the shorter base. The shorter base is half the length of the longer base. Write a formula for the area of this trapezoid in terms of the altitude.