The sum of two adjacent sides of a parallelogram is 18 cm. What is the perimeter of the parallelogram in cm?
一个平行四边形相邻两条边的和是18厘米，这个平行四边形的周长是多少厘米？
<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<result>36</result>