A rectangular cardboard with a length of 20 cm and a width of 10 cm is rotated once about its length and width as axes respectively. What is the volume of the largest cylinder obtained in cubic centimeters?
一个长方形纸板的长是20厘米，宽是10厘米，分别以它的长与宽为轴旋转一周，所得的最大圆柱体的体积是多少立方厘米．
<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400 * 10</gadget>
<output>12_560</output>

<result>12_560</result>