Final answer:
To find the length of each side of the square garden with an 80ft perimeter, divide the perimeter by 4. Each side is 20ft long.
Step-by-step explanation:
Jess wants to place a stone border around her square garden with a perimeter of 80ft. The perimeter of a square is calculated by adding the lengths of all four sides together. Since all sides of a square are equal in length, we can find the length of one side by dividing the total perimeter by the number of sides, which is four.
To calculate: Length of each side = Total Perimeter / Number of sides = 80ft / 4 = 20ft.
Therefore, the length of each side of Jess's square garden is 20 feet.