与动点相关的定值问题是平面几何命题中颇具挑战性的一类问题,弄清楚命题中动点与定点之间的关系,是解决这类问题的关键。从定值已知或未知两个方面探究这类问题的证明思路和方法,对于培养学生运动的观点和动定结合的思想、提高学生分析问题和解决问题的能力,都是十分有益的。 The fixed point problem related to fixed point is a challenging one in plane geometric proposition. To understand the relationship between fixed point and fixed point in proposition is the key to solve this kind of problem. Prove that this kind of problem can be proved from two aspects, that is, the known value or the unknown value. It is very beneficial to cultivate students ’viewpoint of the movement and the combination of thinking and improving students’ ability of analyzing and solving problems.