When the distance between the feet of the compass is 5 cm, what is the circumference of the circle drawn in cm?
当圆规两脚间的距离为5厘米时，画出圆的周长是多少厘米．
<gadget id="calculator">2 * 3.14 * 5</gadget>
<output>31.4</output>

<result>31.4</result>