



 
Hi Rose, Here is my "nottoscale" sketch of your driveway. The volume of fill required is the area of the triangular crosssection, shaded brown, times the length of 30 feet. You probably want the volume in cubic yards so first convert all the measurements to yards. The surface is 30/3 = 10 yards by 10 yards and the height of the triangular fill crosssection is 243 = 21 inches which is 21/36 = 7/12 yards. Hence the area of the triangular crosssection is
Thus the volume of fill required is
I hope this helps,  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 