rectangular vegetable field is 12 meters wide and twice as long as it is wide. What is the perimeter of the vegetable field in meters?
一块长方形菜地，宽是12米，长是宽的两倍，这块菜地的周长是多少米？
<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<gadget id="calculator">24 + 12</gadget>
<output>36</output>

<gadget id="calculator">36 * 2</gadget>
<output>72</output>

<result>72</result>