There is 0.52 meters left after a rope wraps around the big tree 3 times. If the rope is 19.36 meters long, what is the radius of the big tree in meters?
一根绳子绕大树3圈后还剩0.52米，如果这根绳子长19.36米，这棵大数的半径是多少米？
<gadget id="calculator">19.36 - 0.52</gadget>
<output>18.84</output>

<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">18.84 / 3 / 6.28</gadget>
<output>1</output>

<result>1</result>