You can put this solution on YOUR website! The diagonal of the square is inches, since an edge is 6 inches long. The radius of the circle is then half of this, or inches. Hence the area of the circle is square inches. The area of the square is 36 square inches.
The area of one segment, by symmetry, is a quarter of the difference between the area of the circle and the area of the inscribed square, or
square inches.