Dad used iron wire to form a rectangular frame with a length of 37 cm and a width of 21 cm, and later changed it into a square. Find the side length of the square?
爸爸用铁丝围成一个长37厘米′宽21厘米的长方形框架，后来把它改成一个正方形，求正方形的边长？
<gadget id="calculator">37 + 21</gadget>
<output>58</output>

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

<gadget id="calculator">58 * (1/2)</gadget>
<output>29</output>

<result>29</result>