Master Feng makes a cuboid ventilation pipe, the mouth of the pipe is a square with a side length of 30 cm, and the length of the pipe is 2 meters. How many square meters of iron sheet is needed?
冯师傅制作一根长方体通风管，管口是边长30厘米的正方形，管长2米，需要多少平方米的铁皮．
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) * 4 * 2</gadget>
<output>12/5 = around 2.4</output>

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