A rectangular wall is 2 meters wide and three times as long as it is wide, find the perimeter of the wall.
长方形墙面宽2米，长是宽的3倍，求墙面的周长．
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<gadget id="calculator">6 + 2</gadget>
<output>8</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<result>16</result>