Make a cylindrical ventilation pipe with iron sheets, the length of the ventilation pipe is 5 decimeters, and the diameter of the cross section is 2.4 decimeters. How many square decimeters of iron sheet is needed to make this ventilation pipe?
用铁皮做一根圆柱形通风管，通风管长5分米，横截面的直径为2.4分米．做这根通风管至少需要多少平方分米的铁皮？
<gadget id="calculator">3.14 * 2.4 * 5</gadget>
<output>37.68</output>

<result>37.68</result>