A wire can just enclose a circle with a diameter of 6 cm. If it encloses a square, what is the side length of this square?
一根铁丝正好能围成直径是6厘米的圆，如果把它围成一个正方形，则这个正方形的边长是多少？
<gadget id="calculator">6 / 4</gadget>
<output>3/2 = around 1.5</output>

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

<result>4.71</result>