



 
Hi Carlos, I drew a rough sketch, not to scale The volume of fill is the area of the cross section times the length of 80 fet. The cross section is a trapezoid and the area of a trapezoid is the average of the lengths of the parallel sides times the distance between the parallel sides. I want all the dimensions in feet so the parallel sides are of length $\large \frac{5}{12}$ feet and $\large \frac{2}{12}.$ Hence the volume of fill required is \[\frac12 \left( \frac{5}{12} + \frac{2}{12} \right) \times 112 \times 80 \mbox{ cubic feet.}\] There are 27 cubic feet in a cubic yard so divide the volume in cubic feet by 27 to obtain the volume in cubic yards. Harley  


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