A rectangular lawn is 36 meters long and 24 meters wide, surrounded by fences. How long is the fence in meters?
一块长方形的草坪，长36米，宽24米，四周都围上篱笆．求篱笆长多少米？
<gadget id="calculator">36 + 24</gadget>
<output>60</output>

<gadget id="calculator">60 * 2</gadget>
<output>120</output>

<result>120</result>