在统编教材《几何》中,“三点共线”问题是不乏其例的.这类问题是平面几何教学的难点之一.学生对“三点共线”问题之所以感到困惑和棘手,主要表现在两个方面:一是认为“无章可循”,觉得证明三点共线问题无据可依,不好下手,不象证明四点共圆那样有规律.二是感到“有口难言”,知道那样证,就是说不清,往往似是而非,答非所问. In the textbook “Geometry”, the “three-point collinear” problem is no shortage of examples. This kind of problem is one of the difficulties in teaching plane geometry. The students are puzzled and intractable about the “three-point collinear” problem. Mainly in two aspects: First, that “there is no rule to follow”, feel that the proof of the three-point collinear problem has no basis to follow, not easy to start, not as regular four-point co-circulation. Second, feel that “have ”I can’t say anything". Knowing to prove it means that it is unclear. It is often plausible and unanswered.