What is the perimeter of a rectangle whose length is 6 cm and whose width is 2 cm less than its length?
长是6厘米，宽比长少2厘米的长方形，它的周长是多少厘米
<gadget id="calculator">6 - 2</gadget>
<output>4</output>

<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<result>20</result>