There is a big clock hanging in the hall of the school teaching building. Its hour hand is 40 cm long. How many centimeters does the tip of the hour hand travel from 10:00 a.m. to 10:00 p.m. in one day?
学校教学楼的大厅内挂着一只大钟，它的时针长40厘米．一天从上午10时到晚上10时，这根时针的尖端所走的路程是多少厘米？
<gadget id="calculator">40 * 2 * 3.14</gadget>
<output>251.2</output>

<result>251.2</result>