When drawing a circle, the circumference of the circle is 15.7 centimeters, what is the distance between the two feet of the compass in centimeters?
画圆时，圆的周长为15.7厘米，那么圆规两脚间的距离是多少厘米．
<gadget id="calculator">15.7 / 3.14 / 2</gadget>
<output>2.5</output>

<result>2.5</result>