As shown in the figure below, the area of a square is 2 square decimeters, and the area of a circle is calculated

As shown in the figure below, the area of a square is 2 square decimeters, and the area of a circle is calculated

π R2 = 3.14 × 2 = 6.28 (square decimeter); a: the area of a circle is 6.28 square decimeter