近年来,高考涉及焦点三角形的问题颇多.本文介绍一个重要结论.应用本文结论解决这类问题,不但使较复杂的问题简单化,而且计算简捷,不易出错.结论已知椭圆xa22+by22=1(ab0),F1(-c,0),F2(c,0)(其中c2=a2-b2)为左、右焦点,椭圆上的任意一点P(x0,y0)与两焦点构成的三角形△PF1F2 In recent years, there have been many problems involving focus triangles in the college entrance examination. This paper introduces an important conclusion. Applying the conclusions of this paper to solve these problems not only simplifies the more complicated problems, but also makes calculation simple and error-prone. Conclusion Known ellipses xa22+by22= 1(ab0),F1(-c,0),F2(c,0) (where c2=a2-b2) is the left and right focus, any point on the ellipse P(x0,y0) and the two focus triangles △PF1F2