The minute hand of a small alarm clock is 4 cm long. After half an hour, what is the distance traveled by its tip in cm?
一只小闹钟的分针长4cm，经过半小时，它的尖端走过的路程是多少cm
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 4 * 1</gadget>
<output>12.56</output>

<result>12.56</result>