A cylindrical bucket is 62.8cm high, and its side is a square. How much iron sheet is needed to make such a bucket without a lid?
一个圆柱形水桶，高62.8cm，它的侧面展开是一个正方形，做这样的无盖水桶至少需要多少铁皮？
<gadget id="calculator">62.8 * 62.8</gadget>
<output>3_943.84</output>

<gadget id="calculator">62.8 / 3.14 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<gadget id="calculator">3_943.84 + 314</gadget>
<output>4_257.84</output>

<result>4_257.84</result>