Question 1047024
The cutting starts from the original perimeter of the rectangle and goes INWARD.   The help to make this interpretation is, "3/4 sq mi ... is to remain."


How wide?  Let this be the variable, x.


Initial area before cutting the trees away:  {{{1*2=2*squareMiles}}}.


Area remaining after cutting the width of x around the forest, rectangle:  {{{highlight((1-2x)(2-2x)=3/4)}}}.
This is the equation to solve.


That was the analysis including forming the equation to be solved.  You can probably solve the resulting equation without help ?