A circular flowerbed is drawn on paper with a scale of 1:500 and its circumference is 6.28 cm. Find the actual area of the flowerbed.
一个圆形花圃，用1：500的比例尺画在纸上周长是6.28厘米，求花圃的实际面积．
<gadget id="calculator">31.4 / 3.14</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<result>25</result>