If a circle is drawn with a compass and the distance between the legs of the compass is 3 cm, what is the circumference of the circle in cm?
如果用圆规画圆，圆规两脚之间的距离是3厘米，那么圆的周长是多少厘米．
<gadget id="calculator">2 * 3.14 * 3</gadget>
<output>18.84</output>

<result>18.84</result>