The hour hand of a clock is 4 cm long, how many centimeters does the tip of the hour hand move in a day and night?
一个时钟的时针长4厘米，这个时针的尖端一昼夜走了多少厘米．
<gadget id="calculator">3.14 * 4 * 2 * 2</gadget>
<output>50.24</output>

<result>50.24</result>