论文部分内容阅读
解答平面几何题中,添加辅助线是常用而且重要的手段,是连接已知与未知的桥梁。添辅助线要遵循三个原则:一分解的原则:即把复杂图形分解为三角形.二集中的原则:把已知与未知的元素集中到一个三角形或两个全等、相似的三角形中.三挂勾的原则.把图形中没有联系的元素,通过添辅助线实现联系。添辅助常采用平移、对称和旋转三种手段.常用的添辅助线的规律有以下几种:一已知条件中有中点、中位线时常延长中线或中位线的一倍,或过中点作出另一边的平行线,通过平移制造全等三角形或是找出线段间
To solve plane geometry problems, adding auxiliary lines is a common and important means to connect known and unknown bridges. There are three principles to follow to add an auxiliary line: The principle of decomposition: the decomposition of complex graphics into triangles. The principle of two sets: the concentration of known and unknown elements into one triangle or two congruent, similar triangles. The principle of hooking. To connect elements that are not linked in the graph by adding auxiliary lines. Tim assist is often used for translation, symmetry and rotation. The commonly used rules for adding auxiliary lines are the following: One known condition has a midpoint, and the middle bit line often extends the midline or midline, or twice. The middle point makes a parallel line on the other side, which translates into a congruent triangle or finds a line segment