Question 804084
The basicly asks for the area of the rectangle.

w for width
15w for length


We can only assume that the 160 feet of fencing was equivalent to the perimeter of the rectangular garden.  {{{2(w+15w)=160}}}.   
Solve for w.  Once found, compute {{{15*w}}}.


Area is {{{w*15w=15w^2}}}