If the minute hand of a large clock is 30 cm long, how many centimeters does the tip of the minute hand travel for one hour?
一个大钟，它的分针长30厘米，如果走一个小时，它的分针的尖端走过了多少厘米？
<gadget id="calculator">2 * 3.14 * 30</gadget>
<output>188.4</output>

<result>188.4</result>