论文部分内容阅读
“对称性”是初中几何中的重要性质之一,对称分为轴对称和中心对称. 关于轴对称和中心对称有如下性质:1.轴对称(或中心对称)的两个图形全等;2.轴对称的两条直线平行或相交于对称轴上一点;3.轴对称的两个图形上的对称点所连线段被对称轴垂直平分;4.中心对称的两个图形,对称点所连线段被对称中心平分. 在解决几何问题时,常常利用对称的性质来寻求辅助线的作法,这种方法我们称为对称法,对称法是几何变换的重要方法之一.现举例说明如下:
“Symmetry” is one of the important properties of junior high school geometry. Symmetry is divided into axial symmetry and central symmetry. About the axisymmetric and central symmetry, there are the following properties: 1. Two axisymmetric (or centrosymmetric) two-elements; The two axes of symmetry are parallel or intersect at a point on the axis of symmetry; 3. The line segments of the symmetry points on the two axisymmetrical graphs are equally divided vertically by the axis of symmetry; 4. The two symmetries of the center are symmetrical. The line segment is divided equally by the center of symmetry. When solving geometric problems, the symmetry property is often used to search for auxiliary lines. This method is called symmetrical method. Symmetric method is one of the important methods of geometric transformation. :