A cylindrical bucket without a lid, with a bottom diameter of 4dm and a height of 5dm, how many dm**2 planks are needed to make such a bucket?
一个圆柱形无盖水桶，底面直径4dm、高5dm，做一个这样的水桶至少需要多少dm**2的木板？
<gadget id="calculator">3.14 * 4 * 5</gadget>
<output>62.8</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">62.8 + 12.56</gadget>
<output>75.36</output>

<result>75.36</result>