A rectangular lawn is 80 meters long and 40 meters wide. If you walk around it twice, how long is the path?
一个长方形草地长80米，宽40米，围着它散步两圈，走的路长多少米？
<gadget id="calculator">80 + 40</gadget>
<output>120</output>

<gadget id="calculator">120 * 2 * 2</gadget>
<output>480</output>

<result>480</result>