The hour hand of a wall clock is 5 cm long, how many centimeters does the tip of the hour hand move after 12 hours?
一只挂钟的时针长5厘米，经过12小时，时针尖端移动了多少厘米．
<gadget id="calculator">3.14 * 5 * 2</gadget>
<output>31.4</output>

<result>31.4</result>