Two trapezoids with upper base, lower base and height of 4 meters, 5 meters and 6 meters respectively are used to form a parallelogram. What is the area of the parallelogram?
用两个上底、下底、高分别是4米、5米、6米的梯形拼成一个平行四边形，那么这个平行四边形的面积是多少．
<gadget id="calculator">9 * 3</gadget>
<output>27</output>

<result>27</result>