What is the volume of a trapezoid prism?

The volume of any right prism is the area of the base, in this case a trapezoid, multiplied by the height of the prism. The formula for the area of a trapezoid is A = 1/2h(a + b) where a and b are the bases of the trapezoid (the parallel sides). Once you calculate the area of the trapezoidal base of the prism, multiply that number by its height to get its volume.