相似三角形是初中几何的重点内容,也是今后学习“解直角三角形”和“圆”的基础.相似三角形的内容较为复杂,图形千变万化,学习起来很不容易,但是如果认真观察这部分图形的结构特征,及时从复杂的图形中发现或构造常见的基本图形,掌握这些基本图形的构成、形式及所具有的性质,问题往往会简捷获解.现列举相似三角形中最常见的基本图形 Similar triangles are the key content of junior high school geometry, and they are also the basis for future study of “resolving right-angled triangles” and “circles.” The content of similar triangles is more complex and the graphics are ever-changing. It is not easy to learn, but if you carefully observe the structural features of this part of the figure , Find or construct common basic graphics in a timely manner from complex graphics, and grasp the composition, form, and nature of these basic graphics. Problems are often solved simply and easily. The most common basic graphics in similar triangles are now enumerated.