Answer :
The length of the fence is l = 20 ft.
The width of the fence is w = 15 ft.
The formula for the perimeter of fence,
[tex]P=2(l+w)[/tex]Determine the perimeter of fence.
[tex]\begin{gathered} P=2(20+15) \\ =2\cdot35 \\ =70 \end{gathered}[/tex]Thus perimeter of fence is 70 ft.