A wire encloses a square with a side length of 6.28 meters. If the square is transformed into a circle, what is the diameter of the circle in meters?
一根铁丝围成一个边长是6.28米的正方形，如果把这个正方形改围成一个圆，这个圆的直径是多少米．
<gadget id="calculator">4 / 3.14</gadget>
<output>1.273885</output>

<gadget id="calculator">6.28 * 1.273885</gadget>
<output>7.999998</output>

<result>7.999998</result>