A rectangular vegetable field, the sum of its length and width is 28 meters, what is the perimeter of this rectangular vegetable field in meters?
一块长方形菜地，长与宽的和是28米，这个长方形菜地的周长是多少米？
<gadget id="calculator">28 * 2</gadget>
<output>56</output>

<result>56</result>