A wire can enclose a circle with a radius of 3 cm. If the wire is re-enclosed into a square, what is the side length of the square?
一根铁丝可以围成一个半径是3厘米的圆．如果把这根铁丝重新围成一个正方形，这个正方形的边长是多少？
<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3.14 * 3 * (1/2)</gadget>
<output>4.71</output>

<result>4.71</result>