A rectangular lawn is 80 meters long and 50 meters wide. If you walk around it, how long is the path?
一个长方形草地长80米，宽50米，围着它散步走一圈，走的路长多少米？
<gadget id="calculator">80 + 50</gadget>
<output>130</output>

<gadget id="calculator">130 * 2</gadget>
<output>260</output>

<result>260</result>