The area of a trapezoid can be calculated using the formula A = (1/2) * (a + b) * h, where a and b are the lengths of the two parallel sides, and h is the height.
In this case, the lengths of the parallel sides are 6 in and 12 in (let's call them a and b, respectively). The height of the trapezoid is 9 in.
Plugging these values into the formula:
A = (1/2) * (6 + 12) * 9
A = (1/2) * 18 * 9
A = 9 * 9
A = 81 square inches
Therefore, the area of the trapezoid is 81 square inches.