一、知识链接1.轴对称图形的对称轴有的只有一条,有的则有许多条;2.线段、角、长方形、菱形、等腰三角形、圆都是轴对称图形;3.轴对称的两个图形一定全等,但两个全等的图形不一定是轴对称图形;4.对称轴是直线而不是线段;5.如果两个图形的对应点的连线被同一条直线垂直平分,那么这两个图形关于这条直线成轴对称. First, the knowledge link 1. Symmetrical axis of symmetry axis, there are only one, while others are many; 2. Line segments, corners, rectangles, diamonds, isosceles triangles, circles are axisymmetric graphics; 3. Axisymmetric The two graphics must be congruent, but the two congruent graphics are not necessarily axisymmetric graphics; 4. The axis of symmetry is a straight line rather than a line segment; 5. If the connection points of two graphics corresponding points are vertically bisecting the same straight line, Then the two graphs are axisymmetric about this line.