A rectangular rapeseed field has a circumference of 28 meters, a length of 9 meters, and a width of 9 meters?
一块长方形油菜地周长是28米，长是9米，宽是多少米？
<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">14 - 9</gadget>
<output>5</output>

<result>5</result>