The area of the reactangle is calculates using the following formula:
[tex]A=w\cdot l[/tex]Where
A: area
w: wisth
l: lenght
You can write this formula in terms of the length by dividing the Area by the width:
[tex]l=\frac{A}{w}[/tex]If the area is A=s feet² and the width is w=6 feet, then the length is
[tex]l=\frac{s}{6}[/tex]