Area of garden = 81 ft²
Area of square = side²
[tex] \rm \implies side ^{2} = 81 \\ \\ \rm \implies side = \sqrt{81} \\ \\ \rm \implies side = \sqrt{ {9}^{2} } \\ \\ \rm \implies side = 9 \: ft[/tex]
Perimeter of square = 4 × Side
= 4 × 9
= 36 ft
[tex] \therefore [/tex] Fencing needed by Janet = 36 ft
