A rectangular wire frame with a length of 12 cm and a width of 6 cm is folded into a square. What is the side length of the square?
用长是12cm、宽是6cm的长方形的铁丝框折成一个正方形，这个正方形的边长是多少？
<gadget id="calculator">12 + 6</gadget>
<output>18</output>

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

<gadget id="calculator">18 * (1/2)</gadget>
<output>9</output>

<result>9</result>