The diagonal of the square is √(4? +4? ) =4√2 cm

Radius of great circle: 2√2 cm.

Great circle area: 2√2×2√2×π=8π square centimeter.

Radius of small circle: 2 cm

Area of small circle: 2×2×π=4π square centimeter.

8π-4π=4π= 12.56 cm2

Answer: The area difference between two circles is 12.56 square centimeters.