A ribbon can form a rectangle with a length of 5 cm and a width of 3 cm. If it is a square, what is its side length?
一根彩带可以围成一个长5厘米、宽3厘米的长方形．如果把它围成一个正方形，它的边长是多少厘米？
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

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

<gadget id="calculator">8 * (1/2)</gadget>
<output>4</output>

<result>4</result>