Final answer:
The side length of the garden is 8 feet.
Step-by-step explanation:
To find the side length of the garden given the area is 64 square feet, we need to determine the length of one side of a square with an area of 64 square feet. Since the area of a square is equal to the side length squared, we can find the side length by taking the square root of the area. In this case, the square root of 64 is 8, so the side length of the garden is 8 feet.