Since you already have the radius (7.53), you must find the area of the circle and subtract the area of the square from that. So, you use the formula A = r^2 where r is 7.53. From there, you get about 178.1311 square cm. Then, knowing the diagonal (7.53 * 2 or 14.06), you get the side length to be about 10.65. Squaring that, we get 113.4225. Subtracting, we get the answer to be about 64.7 square centimeters.