Obviously use a compass to draw a circle with a circumference of 31.4cm, what is the distance in cm between the two feet of the compass.
明明用圆规画一个周长是31.4cm的圆，圆规两脚间的距离是多少cm．
<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

<result>5</result>