中考试卷中,经常出现已知平面直角坐标系中的两点,在已知图形上来找第三点,使得以这三点为顶点的三角形为等腰三角形。由于第三点的图形未知,一些同学感到难以下手,还有一些同学能做到答案,不过答案不完整,究其原因,实质是未能掌握解决问题的一般方法,从而出现错解与少解。 In the examination paper, there are often two known points in the Cartesian coordinate system, looking for the third point in the known graph, so that the triangle with the three vertices is the isosceles triangle. As the third point of the figure is unknown, some students feel difficult to start, there are some students can do the answer, but the answer is not complete, the reason, in essence, is unable to grasp the general method of solving problems, resulting in misunderstanding and less solution .