There is a piece of iron wire that is used to form a rectangle with a length of 8 cm and a width of 4 cm. If this wire is used to form a square, what is the side length of the square?
有一根铁丝，用它围成一个长8厘米，宽4厘米的长方形，如果用这根铁丝围成一个正方形，这个正方形的边长是多少厘米？
<gadget id="calculator">8 + 4</gadget>
<output>12</output>

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

<gadget id="calculator">12 * (1/2)</gadget>
<output>6</output>

<result>6</result>