It is 2 decimeters to make the bottom surface radius with iron sheet, the cylindrical garbage bin (without cover) of 5 decimeters in height, please do the math, how many square decimeters of iron sheet do you need at least to make such a garbage bin?
用铁皮制作底面半径是2分米，高5分米的圆柱形垃圾桶(没有盖)，请你算一算，制作这样一个垃圾桶至少需要多少平方分米的铁皮？
<gadget id="calculator">2 * 3.14 * 2 * 5</gadget>
<output>62.8</output>

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

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

<gadget id="calculator">62.8 + 12.56</gadget>
<output>75.36</output>

<result>75.36</result>