文[1]给出了三角形重心的一个向量性质.受此启发,笔者对三角形内心和旁心作了类比探究,发现三角形内心与旁心也有类似性质.命题1如图1,点I为△ABC的内切圆的圆心,BC=a,CA=b,AB=c.过点I的直线l与直线AB,AC,BC分别交于D,E,F三点,且(?)=x_0(?)=y_0 The paper [1] gives a vector property of the center of gravity of the triangle. Inspired by this, the author makes an analogy to the inner and the inner side of the triangle and finds that the inner and the inner side of the triangle also have similar properties. Proposition 1 is shown in Figure 1, and the point I is △ The center of the circle of the inscribed circle of ABC, BC=a, CA=b, AB=c. The straight line l passing through point I intersects with the straight line AB, AC, and BC respectively at points D, E, and F, and (?)=x_0 (?)=y_0