The side length of a square vegetable field is 8 meters, and a fence should be surrounded around it. What is the length of the fence?
一块正方形菜地的边长是8米，要在它的四周围一圈栅栏，栅栏长多少米．
<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<result>32</result>