A rectangular piece of land is 4 meters long and 3 meters wide. Uncle Wang surrounded the largest square vegetable field with a fence. How many meters is the fence?
一块长方形土地，长4米，宽3米．王大伯在里面用篱笆围出一块最大的正方形菜地，求篱笆长多少米？
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<result>12</result>