The garden is described as having a circular shape. The diameter is 9 feet. The length of fencing material needed to fence around the outside of her garden refers to the perimeter or the circumference of the circular garden.
The circumference of a circle is given as;
[tex]\begin{gathered} \text{Cir}=2\pi r \\ r=\frac{\text{diameter}}{2} \\ r=4.5 \\ \text{Cir}=2\times3.14\times4.5 \\ \text{Cir}=28.26 \end{gathered}[/tex]Therefore, Rose would need 28.26 feet of fencing material