三等角型相似三角形是指以等腰三角形(等腰梯形、直角梯形或等边三角形)为背景,把一个与底角相等的顶点放在底边进行旋转的题型.一般有如图1所示几种,这是相似三角形中最简单又最常见的问题,和我们平时经常看见“A”和“8”字型一样, Triangular similar triangle refers to the isosceles triangle (isosceles trapezoid, right trapezoid or equilateral triangle) as the background, the bottom corner and a vertex equal rotation on the bottom of the problem. Generally as shown in Figure 1 This is the simplest and most common problem in similar triangles, and as we often see, the “A” and “8” fonts are often seen.