A rectangular flower bed is 9 meters long and 6 meters wide. What is the perimeter of this flower bed?
一个长方形花坛，它的长是9米，宽是6米．这个花坛的周长是多少米？
<gadget id="calculator">9 + 6</gadget>
<output>15</output>

<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<result>30</result>