rectangle with a length of 15 cm and a width of 7 cm is surrounded by a piece of iron wire. If it is changed into a square, what is the side length of this square in cm?
用一根铁丝围成一个长为15厘米，宽为7厘米的长方形，如果将它改成一个正方形，这个正方形的边长是多少厘米？
<gadget id="calculator">15 + 7</gadget>
<output>22</output>

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

<gadget id="calculator">22 * (1/2)</gadget>
<output>11</output>

<result>11</result>