PLEASE HELP A farmer has a field in the shape of a trapezoid, formed by three congruent isosceles triangles, as shown below. He wants to plant vegetation in the green shaded area and pour concrete in the remaining area. a. What area of the field does the farmer plan to use for vegetation planting? Round your answer to the nearest tenth of a square yard.

b. If a bag of top soil costs $12 and covers 36 square yards, how much will it cost the farmer to cover the vegetation part of his field with the top soil?