A rectangular vegetable field is 20 meters long and 8 meters wide. Xiaohong walked around the vegetable field, how many meters did she walk in total?
一块长方形菜地，长20米，宽8米．小红绕菜地走一圈，一共走了多少米？
<gadget id="calculator">20 + 8</gadget>
<output>28</output>

<gadget id="calculator">2 * 28</gadget>
<output>56</output>

<result>56</result>