A rectangle with a length of 20 meters and a width of 16 meters is surrounded by a piece of iron wire. If it is changed into a square, what is the length of the side of the square?
用一根铁丝围成一个长20米，宽16米的长方形，如果改成正方形，围成正方形的边长是多少米．
<gadget id="calculator">20 + 16</gadget>
<output>36</output>

<gadget id="calculator">36 * 2</gadget>
<output>72</output>

<gadget id="calculator">72 / 4</gadget>
<output>18</output>

<result>18</result>