A piece of iron wire can be used to make a rectangle with a length of 28 cm and a width of 12 cm. If it is made into a square, what is the side length of the square?
用一根铁丝可以做成一个长28厘米，宽12厘米的长方形，如果改做成一个正方形，正方形的边长是多少？
<gadget id="calculator">28 + 12</gadget>
<output>40</output>

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

<gadget id="calculator">40 * (1/2)</gadget>
<output>20</output>

<result>20</result>