Xiaoming's family bought a 31.4-meter-long fence, which can form a circular chicken coop with a diameter of several meters.
小明家买了31.4米长的篱笆，能围成直径多少米的圆形鸡栏．
<gadget id="calculator">31.4 / 3.14</gadget>
<output>10</output>

<result>10</result>