Uncle Li has a 471-meter-long iron wire, and plans to enclose it into a circular bullpen and circle the cowpen three times. How many square meters does this bullpen occupy?
李叔叔有471米长的铁丝，计划把它围成一个圆形牛栏，并绕牛栏3圈，这个牛栏占地多少平方米？
<gadget id="calculator">471 / 3</gadget>
<output>157</output>

<gadget id="calculator">157 / 2 / 3.14</gadget>
<output>25</output>

<gadget id="calculator">25 ** 2</gadget>
<output>625</output>

<gadget id="calculator">3.14 * 625</gadget>
<output>1_962.5</output>

<result>1_962.5</result>