Use a compass to draw a circle with a circumference of 21.98cm, what is the distance between the two feet of the compass?
用圆规画一个周长是21.98cm的圆，那么圆规两脚之间的距离是多少？
<gadget id="calculator">21.98 / 3.14 / 2</gadget>
<output>3.5</output>

<result>3.5</result>