A wire can form a square with a side length of 4.71 cm, which can be changed to form a circle. What is the radius of this circle?
一根铁丝可以围成边长4.71厘米的正方形，改围成一个圆，这个圆的半径是多少？
<gadget id="calculator">4 / 3.14 / 2</gadget>
<output>0.636943</output>

<gadget id="calculator">4.71 * 0.636943</gadget>
<output>3.000002</output>

<result>3.000002</result>