中考题目中常常会结合具体情境,或结合三角形、四边形、圆、平面直角坐标系等知识点,求两个线段和的最小值问题,这类题型乍看起来头绪复杂,让人无从下手,但认真观察后,往往能从课本的内容或思想方法上找到影子,关键是对基本知识点和图形的认识和掌握,并能灵活运用.而这类问题的原型是苏科版八年级上册的第一章“轴对称图形”复习题中的第9题.如图1,点A、B在直线l同侧,点B′是点B关于l The examination questions often combine the specific situation, or with the triangle, quadrangle, circle, plane rectangular coordinate system and other knowledge points, find the minimum of two lines and the problem, such questions at first glance seem clues, people can not start, However, after careful observation, often find the shadow from the textbook content or thinking method, the key is to understand and master the basic knowledge points and graphics, and can be flexibly applied.The prototype of such problems is Su Ke version eighth grade The first chapter “axisymmetric graphics” review questions in question 9. As shown in Figure 1, points A, B in the same line l, point B ’is the point B about l