The bottom surface of a section of ventilation pipe is a square with a side length of 2 decimeters and a height of 3 meters. How many square meters of iron sheet should be used to make such a section of ventilation pipe?
一节通风管的底面是边长2分米的正方形，高3米，做这样一节通风管至少用铁皮多少平方米．
<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 4 * 3</gadget>
<output>12/5 = around 2.4</output>

<result>12/5 = around 2.4</result>