ribbon can form a rectangle with a length of 9 cm and a width of 8 cm. If it is used to form a square, what is the side length of the square?
一条丝带可以围成一个长9厘米，宽8厘米的长方形，如果用它围成一个正方形，正方形的边长是多少厘米？
<gadget id="calculator">9 + 8</gadget>
<output>17</output>

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

<gadget id="calculator">17 * (1/2)</gadget>
<output>17/2 = around 8.5</output>

<result>17/2 = around 8.5</result>