The hour hand of Xiaoliang's wall clock is 8 cm long, and the minute hand is 10 cm long. He does his homework from 4:05 to 4:50, please help him calculate, what is the distance traveled by the tip of the minute hand when Xiao Liang is doing his homework?
小亮家的挂钟时针长8厘米，分针长10厘米．他从4：05～4：50这段时间做作业，请你帮他算一算，小亮做作业这段时间分针针尖走过的路程是多少？
<gadget id="calculator">45 / 60</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2 * 3.14 * 10 * (3/4)</gadget>
<output>47.1</output>

<result>47.1</result>