What Is Trapezoid?
A trapezoid is a quadrilateral (a four-sided shape) with exactly one pair of parallel sides, usually called the bases. The other two sides, called legs, don't have to be parallel or equal in length. Its area is the average of the two parallel sides, multiplied by the height between them.
Example
A trapezoid with parallel sides of 8 and 14, and a height of 5 between them, has an area of ((8 + 14) / 2) × 5 = 55.