Answer :

The formula used to calculate the perimeter of the farm is

[tex]\begin{gathered} \text{Perimeter} \\ =2(l+w) \\ \text{where,} \\ l=9\text{miles} \\ w=4\text{miles} \end{gathered}[/tex]

By substituting the values in the formula above, we will have

[tex]\begin{gathered} \text{Perimeter}=2(l+w) \\ \text{Perimeter}=2(9+4) \\ \text{Perimeter}=2\times13 \\ \text{Perimeter}=26\text{miles} \end{gathered}[/tex]

Hence,

The perimeter of the farm = 26 miles