The minute hand of a clock is 20 cm long. What is the distance traveled by the tip of the minute hand in 15 minutes? (π takes 3.14)
一只挂钟的分针长20厘米，经过15分钟，分针的尖端所走的路程是多少厘米．(π取3.14)
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">3.14 * 20 * 2 * (1/4)</gadget>
<output>31.4</output>

<result>31.4</result>