定义椭圆或双曲线上一点和两焦点组成的三角形叫做焦点三角形;有一个角为直角的焦点三角形叫做焦点直角三角形．为了减少篇幅和方便叙述,先介绍几个一般性结论．性质P是椭圆x2/a2+y2/b2=1(a>c≥b>0,c是半焦距)或双曲线x2/a2-y2/b2=1(a>0,b>0,c是半焦距)上的一点,O是原点,E,F是椭圆 The triangle that defines one or two focal points on an ellipse or hyperbola is called a focal triangle; a focal triangle with a right angle is called a focal right triangle. In order to reduce space and facilitate the narrative, first introduce some general conclusions. The property P is an ellipse x2/a2+y2/b2=1 (a>c≥b>0, c is a half focal length) or a hyperbola x2/a2-y2/b2=1 (a>0, b>0,c is A point on the half focal length, O is the origin, E, F is the ellipse