To make 10 cylindrical chimney pipes with a length of 1 meter and a bottom radius of 6 cm, at least how many cm**2 iron sheets are needed.
做10节长1米，底面半径为6cm的圆柱烟囱管，至少需要多少cm**2的铁皮．
<gadget id="calculator">2 * 3.14 * 6 * 1 * 100 * 10</gadget>
<output>37_680</output>

<result>37_680</result>