If the lengths of two adjacent sides of a parallelogram are 6 cm and 5 cm, what is its perimeter in cm?
平行四边形相邻的两条边长是6厘米、5厘米，它的周长是多少厘米．
<gadget id="calculator">6 + 5</gadget>
<output>11</output>

<gadget id="calculator">11 * 2</gadget>
<output>22</output>

<result>22</result>