贵刊2013年第3期刊登了“一条直线与四边形相交的一个性质”的文章,文献[1]用梅涅劳斯定理证明了该性质并探究了几个有趣现象.读后受益匪浅,颇受启发,本文笔者给出性质的面积证法,现写于后,供大家赏析.性质如图1,一条直线与四边形ABCD Published in 2013 the third issue of your “a line and a quadrilateral intersect a character ” article [1] proved the nature with the Menelaus theorem and explored a few interesting phenomena. Shallow, quite inspired, this article gives the nature of the area of ​​the card law, is now written in, for everyone to appreciate. Nature as shown in Figure 1, a straight line and quadrilateral ABCD