The radius of the base of the cylinder is 4cm, the height is 30cm, what is the volume?
圆柱的底面半径为4cm，高是30cm，体积是多少？
<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16 * 30</gadget>
<output>1_507.2</output>

<result>1_507.2</result>