What is the volume of a cylinder whose base radius is 2 cm and whose height is 5 cm?
一个圆柱体，它的底面半径是2厘米，高是5厘米，它的体积是多少．
<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>