A cylindrical bucket without a cover has a bottom diameter of 4dm and a height of 6dm measured from the inside. How many square decimeters of iron sheet are needed to make this bucket?
一只无盖的圆柱形水桶，从里面量得底面直径是4dm，高是6dm，做这只水桶至少需要铁皮多少平方分米？
<gadget id="calculator">3.14 * 4 * 6</gadget>
<output>75.36</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<gadget id="calculator">75.36 + 12.56</gadget>
<output>87.92</output>

<result>87.92</result>