Given, the Smith family has a square shaped vegetable garden.
The area of the garden given = 1600 square feet.
The family wants to fence all sides which means the perimeter of it.
We know that the formula to find the area is
, where s is the side.
So we can write,

To find s , we have to take square root to both sides. We will get,



So we have got the side of the square garden = 40 ft.
Now the perimeter of the square garden = 4s.
So, perimeter =
= 160 ft.
We have got the required answer.
Total fencing needed = 160 ft.