rectangle with a length of 8 cm is surrounded by a wire with a length of 24 cm. What is the width of the rectangle in cm?
用一根长24厘米的铁丝围成一个长8cm的长方形，这个长方形宽是多少厘米？
<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">12 - 8</gadget>
<output>4</output>

<result>4</result>