A rope 15.7 meters long can just wrap 10 times around the trunk of the tree. What is the approximate radius in centimeters of the cross-section of the trunk of this tree?
长15.7米的绳子正好可以绕树的树干10圈．这棵树树干横截面的半径大约是多少厘米？
<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">10 / 6.28</gadget>
<output>1.592357</output>

<gadget id="calculator">15.7 * 1.592357</gadget>
<output>25.000005</output>

<result>25.000005</result>