How many square decimeters of iron sheet is required to make a cylindrical bucket (without a cover) whose height is 5 decimeters and whose bottom circumference is 12.56 decimeters?
用铁皮制成一个高是5分米，底面周长是12.56分米的圆柱形水桶(没有盖)，至少需要多少平方分米铁皮？
<gadget id="calculator">12.56 * 5</gadget>
<output>62.8</output>

<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">12.56 / 6.28</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">62.8 + 12.56</gadget>
<output>75.36</output>

<result>75.36</result>