Draw a pattern with two wires of equal length. One was made into a rectangle with a length of 9 cm and a width of 3 cm. What is the side length of the formed square?
用两根一样长的铁丝作图形．一根做成了长9厘米，宽3厘米的长方形．做成的正方形的边长是多少厘米？
<gadget id="calculator">9 + 3</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>