Question 635050
Length =L
Width=W=L-3
Area=A=4ft^2

Area= Length*Width
A=L*W
{{{4=(L)(L-3)}}}
{{{4=L^2-3L}}}
{{{L^2-3L-4=0}}}
Solve for L
{{{L^2-4L+L-4=0}}}
{{{L(L-4)+1(L-4)=0}}}
{{{(L-4)(L+1)=0}}}
{{{L-4=0}}} OR {{{L+1=0}}}
{{{L=4}}} OR {{{L=-1}}} (unacceptable) 

so L=4

Length =L = 4 ft
Width=W=L-3 = 4-3 = 1ft