Uncle Liu’s family wants to use iron sheets to make the kitchen chimney. The chimney is 3 meters long and the diameter of the bottom is 10 cm. How much iron sheet does it take to make such a chimney?
刘大伯家要用铁皮做厨房的烟囱，烟囱长3米，底面直径是10厘米，做一根这样的烟囱要多少铁皮？
<gadget id="calculator">10 / 10</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 3 * 10</gadget>
<output>94.2</output>

<result>94.2</result>