What Is the Surface Area of a Trapezoid?

The surface area of a trapezoid is calculated using the equation 1/2(a+b)*h, where "a" and "b" are the parallel sides of the trapezoid, and "h" is the vertical height. For example, if side "a" equals three, side "b" equals five and height "h" equals four, then the area equals 1/2(3+5)*4, or 16.