There is a big tree in the park. The students circled the tree 6 times with a 20-meter-long rope, and there is still 1.16 meters left. What is the diameter of the trunk?
公园里有一棵大树，同学们用一根20米长的绳子围绕这棵树绕了6圈，还剩下1.16米，求树干的直径是多少？
<gadget id="calculator">20 - 1.16</gadget>
<output>18.84</output>

<gadget id="calculator">18.84 / 6 / 3.14</gadget>
<output>1</output>

<result>1</result>