A rectangular vegetable field is 8 meters long and 3 meters wide. What is the perimeter of this vegetable field in meters?
一个长方形菜地，长8米，宽3米，这块菜地的周长是多少米．
<gadget id="calculator">8 + 3</gadget>
<output>11</output>

<gadget id="calculator">11 * 2</gadget>
<output>22</output>

<result>22</result>