According to the requirements: as shown in the figure, the square area is 18dm2, find the area of the circle
Suppose the radius of the circle is RDM, then the side length of the square is RDM, because R2 = 18, so the area of the circle is: 3.14 × 18 = 56.52 (DM2); answer: the area of the circle is 56.52 DM2