A square vegetable field with a side length of 6 meters, if one side is against a wall, how many meters should be fenced around the field?
一块正方形菜地，边长6米，如果一面靠墙，要给这块地围上篱笆，要围多少米？
<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>