Use the formula for the area of a trapezoid areaoftrapezoid, where A is area, b1 and b2 are the length of the bases and h is the height, to answer the question. How many square feet of grass are there on a trapezoidal field with a height of 75 ft and bases of 125 ft and 81 ft?

75 * (125+81)/2 = ____ ft^2