A piece of iron wire just forms a rectangle with a length of 4 meters and a width of 2 meters. If this wire is used to form a square, what is the side length of the square?
一根铁丝刚好围成一个长4米，宽2米的长方形，如果用这根铁丝围成一个正方形，那么正方形的边长是多少？
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">6 * (1/2)</gadget>
<output>3</output>

<result>3</result>