If a 20-meter-long rope is wound 3 times around a tree trunk, there will be 1.16 meters more. What is the circumference of the cross-section of the tree trunk in meters?
用20米长的绳子绕一棵树干3圈后多出1.16米，这棵树干的横截面的周长是多少米？
<gadget id="calculator">20 - 1.16</gadget>
<output>18.84</output>

<gadget id="calculator">18.84 / 3</gadget>
<output>6.28</output>

<result>6.28</result>