The hour hand of a clock is 5 cm long, how many centimeters does the tip of the hour hand travel from 6 am to 6 pm.
一个钟表的时针长5厘米，从上午6时到下午6时，时针针尖走过了多少厘米．
<gadget id="calculator">3.14 * 5 * 2</gadget>
<output>31.4</output>

<result>31.4</result>