Stone: 3. 14 times the square of 5 =78.5 (square meter); fallen leaves: 3. 14 times the square of 1 =3. 14 (square meter).

78.5-3. 14 = 75.36m2 78.5 is greater than 3. 14.

A: The water waves generated by stones have a large area of 75.36 square meters.