If a square has a side length of 2 centimeters, what is the volume in cubic centimeters obtained by rotating the square around one side of the square once?
一个正方形的边长2厘米，以正方形的一条边为轴旋转一周所得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>