Question 432784
Let's x feet the length of your garden.Then the width will be:{{{(25-2x)/2}}}feet.

And the area will be: {{{A=x(25-2x)/2}}}, we can write it in the form:

{{{A=-x^2+(25/2)x}}}, that represent a downward parabola, where the value of 

its vertex  is the maximum area. We find the vertex.

{{{x=-b/2a=(-25)/(2)(-2)=25/4}}}.

If you want the maximum area, fens a square with side 25/4 feet.