The area of a square is calculated by multiplying the length of one side by itself. In this case, since each side measures 9 inches, the area can be computed as follows:
Area = side × side = 9 inches × 9 inches = 81 square inches.
Since 81 is already a whole number, rounding it off to the nearest whole number still gives us 81.
Therefore, the area of the square is 81 square inches.