There is a 38-meter-long copper wire, and a coil is wound 4 times, leaving 0.32 meters remaining. What is the diameter of the coil in meters?
有一根38米长的铜线，绕一个线圈4圈，还余0.32米，这个线圈的直径是多少米？
<gadget id="calculator">38 - 0.32</gadget>
<output>37.68</output>

<gadget id="calculator">37.68 / 4 / 3.14</gadget>
<output>3</output>

<result>3</result>