Since 1 yard converts to 3 feet in length, there are 9 square feet in 1 square yard. The area of a perfect square always equals the length of one side squared, written in this case as "3 squared," which has a product of 9.
Since a square is a rectangle, the area may also be determined by multiplying its length by its width (3 x 3). In measuring smaller areas, square feet may be further broken down into square inches. There are 12 inches in 1 foot, so 1 square foot is equal to 144 square inches, or simply 12 squared.