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

<result>2.5</result>