In the decoration of large shopping malls, 10 sections of 12-meter-long cylindrical ventilation pipes need to be made, and the circumference of the bottom surface is 30 cm. How many square centimeters of iron sheets are needed at least?
大型商场装修中需要做10节长12米圆柱形通风管，底面周长是30厘米，至少需要铁皮多少平方厘米？
<gadget id="calculator">12 * 100</gadget>
<output>1_200</output>

<gadget id="calculator">30 * 1_200 * 10</gadget>
<output>360_000</output>

<result>360_000</result>