所谓“等积法” ,是指某些几何问题中 ,可以通过面积相等关系 ,导出其它几何元素之间的关系 ,从而使问题得以解决 .本文通过几个例子 ,说明“等积法”的重要性 ,希望对同学们有所帮助 .例 1　如图 1 ,菱形ABCD的对角线交于点O ,AC =1 6cm ,BD =1 2cm ,求菱形的高 .思路　过D作D The so-called “isopleic method” means that in some geometric problems, the relationship between other geometric elements can be derived through the relationship of area equality, so that the problem can be solved. This article illustrates several important examples of the importance of the “isopleic method”. Sex, hope to help the students. Example 1 As shown in Figure 1, the diagonal of the diamond ABCD intersects at point O, AC =1 6cm, BD =1 2cm, and the diamond is high. The idea is D for D.