A thin iron wire with a length of 31.95 meters has 0.55 meters remaining after 20 turns around a cylinder. What is the approximate diameter of the cross-section of this cylinder?
一根长31.95米的细铁丝，绕一圆柱20圈后还余0.55米，这个圆柱的横截面直径大约是多少米？
<gadget id="calculator">31.95 - 0.55</gadget>
<output>31.4</output>

<gadget id="calculator">31.4 / 20</gadget>
<output>1.57</output>

<gadget id="calculator">1.57 / 3.14</gadget>
<output>0.5</output>

<result>0.5</result>