2001 AIME II Problem 6

Square A B C D is inscribed in a circle. Square E F G H has vertices E and F on \overline{C D} and vertices G and H on the circle. The ratio of the area of square E F G H to the area of square A B C D can be expressed as m / n where m and n are relatively prime positive integers and m<n. Find 10 n+m.