Perimeter is 2(L+W) where L=length W=width.
2(L+W)=64 5/6"=389/6".
L+W=389/12. L=389/12-W, so the relationship can be plotted on a straight line graph.
389/12-W>0 so W<389/12", or W,L<32 5/12".
If W=L the rectangle is a square so L=W=16 5/24". 16 5/24≤{L W}<32 5/12.
Area is variable=LW=L(389/12-L)=389L/12-L^2 which is maximum when L=W=389/24 (area=262.71 sq in approx.)