The two adjacent sides of a parallelogram are 4 decimeters and 6 decimeters respectively, and the distance between a set of opposite sides is 5 decimeters. What is the area of this parallelogram in square centimetres.
一个平行四边形的两条邻边分别是4分米、6分米，一组对边的距离是5分米．这个平行四边形的面积是多少平方分米．
<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<result>20</result>