The formula for the area of a trapezoid is 1/2 (b1 + b2) h So, take your b1 and b2, 12 and 6, and add them together. You get 18. Divide this by 2, and you get 9. Now, multiply 9 by your height, which is 4. 9 x 4 = 36. The area of the trapezoid is 36 square inches.
