Given:
Area of the rectangle is 36 square ft.
Width of the rectangle is 3.97 ft.
Area of the rectangle is,
[tex]\begin{gathered} A=\text{ length }\times\text{ width} \\ 36=l\times3.97 \\ l=\frac{36}{3.97} \\ l=9.07 \\ l\approx9 \end{gathered}[/tex]Answer: the eastimated length of the rectangle is approximately 9 feet.