The hour hand of a wall clock is 2.5 cm long, how many centimeters does the tip of the hour hand travel after 24 hours
一个挂钟的时针长2.5厘米，经过24小时这根时针的尖端走多少厘米
<gadget id="calculator">3.14 * 2.5 * 2 * 2</gadget>
<output>31.4</output>

<result>31.4</result>