To draw a circle with a circumference of 18.84dm, how many centimeters should be measured between the two feet of the compass on the ruler.
要画一个周长是18.84dm的圆，圆规的两脚在直尺上应量取多少cm的距离．
<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">18.84 / 6.28</gadget>
<output>3</output>

<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<result>30</result>