Cut a square with a side length of 2 decimeters into the largest circle, then the area of this circle = how many dm**2.
把边长为2分米的正方形剪成一个最大的圆，则这个圆的面积=多少dm**2．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<result>3.14</result>