What is the volume in cubic centimeters of a shape obtained by rotating a square with a side length of 2 centimeters for one revolution?
以一个边长为2厘米的正方形的一边为转轴，旋转一周所得到的形体的体积是多少立方厘米．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 2</gadget>
<output>25.12</output>

<result>25.12</result>