If the two adjacent sides of a parallelogram are 6 cm and 8 cm respectively, what is its perimeter in cm?
一个平行四边形相邻的两条边分别是6厘米和8厘米，它的周长是多少厘米．
<gadget id="calculator">8 + 6</gadget>
<output>14</output>

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

<result>28</result>