Given that the radius of the base of the cylinder is 2 decimeters and the height is 5 decimeters, find its volume.
已知圆柱的底面半径是2分米，高是5分米，求它的体积．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 5</gadget>
<output>62.8</output>

<result>62.8</result>