Use a compass to draw a circle of 18.84 cm, what is the distance between the two feet of the compass.
用圆规画一个18.84厘米的圆，圆规两脚间的距离是多少．
<gadget id="calculator">18.84 / 3.14 / 2</gadget>
<output>3</output>

<result>3</result>