



 
Hi Katherine, Here is a cross section of the berm you describe (not to scale). Suppose you are at the point P and you walk down the slope towards Q. For every 1 foot you go vertically you go 3 feet horizontally. You need to go 5 feet vertically to arrive at Q and hence you have gone $3 \times 5 = 15$ feet horizontally. The same is true for the slope on the other side of the berm so its width at the base is $15 + 4 + 15 = 34$ feet. Hence the berm covers a rectangle of ground that is 815 feet by 34 feet and thus the area is $815 \times 34 = 27710$ square feet. There are 43560 square feet in an acre so the berm covers $\large \frac{27710}{43560} = 0.64$ acres. Penny
 


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