Make a ventilation pipe with iron sheet, its length is 60cm, and the diameter of the bottom circle is 10cm. How many square centimeters of iron sheet is needed at least?
用铁皮制作1节通风管，它的长是60cm，底面圆的直径是10cm．至少需要铁皮多少平方厘米？
<gadget id="calculator">3.14 * 10 * 60</gadget>
<output>1_884</output>

<result>1_884</result>