Cut a trapezoid into a parallelogram and a triangle. The upper base of the trapezoid is 5dm, the lower base is 8dm, and the height is 6dm. What is the area of the cut parallelogram?
把一个梯形剪成一个平行四边形和一个三角形，梯形的上底是5dm，下底是8dm，高是6dm，剪得的平行四边的面积是多少．
<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<result>30</result>