The length of the minute hand on the clock face is 9 cm, and the length of the hour hand is 6 cm. If the two hands each move for a full circle, how many centimeters will the tip of the minute hand travel further than the tip of the hour hand?
钟面上的分针长9厘米，时针长6厘米，如果两根针各走一周，那么分钟的针尖比时针的针尖多走多少厘米？
<gadget id="calculator">2 * 3.14 * 9</gadget>
<output>56.52</output>

<gadget id="calculator">2 * 3.14 * 6</gadget>
<output>37.68</output>

<gadget id="calculator">56.52 - 37.68</gadget>
<output>18.84</output>

<result>18.84</result>