The floor of the classroom is a rectangle with a length of 8 meters and a width of 6 meters. What is its perimeter?
教室的地面是一个长方形，长8米，宽6米，它的周长是多少？
<gadget id="calculator">8 + 6</gadget>
<output>14</output>

<gadget id="calculator">14 * 2</gadget>
<output>28</output>

<result>28</result>