A cylindrical tin bucket without a cover, 20cm high. The perimeter of the bottom is 62.8cm. How many square centimeters of iron sheet does this bucket need at least?
一个无盖的圆柱形铁皮水桶，高20cm．底面周长是62.8cm．这个水桶至少需要用铁皮多少平方厘米？
<gadget id="calculator">62.8 * 20</gadget>
<output>1_256</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">1_256 + 314</gadget>
<output>1_570</output>

<result>1_570</result>