A rectangular classroom floor is 8 meters long and 6 meters wide, what is its perimeter in meters?
一间长方形教室地面长是8米，宽6米，它的周长是多少米．
<gadget id="calculator">8 + 6</gadget>
<output>14</output>

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

<result>28</result>