To make a metal ventilation pipe with a length of 120 centimeters, a width and a height of 10 centimeters, how many square centimeters of iron sheets are needed at least?
做一节长120厘米，宽和高都是10厘米的铁皮通风管，至少需要铁皮多少平方厘米？
<gadget id="calculator">120 * 10 * 4</gadget>
<output>4_800</output>

<result>4_800</result>