小明把如图所示的平行四边形纸板挂在墙上,完飞镖游戏(每次飞镖均落在纸板上,且落在纸板的任何一个点的机会都相等),则飞镖落在阴影区域的概率是____.
— Listen! Is Professor Johnson giving a report in the hall?
— No, it him. He has gone to Japan.