教学实际中发现,学生往往对根据图形性质求最值的问题比较陌生,本节课通过复习“将军饮马”模型,引导学生参与知识回顾,然后将模型放在几何图形中,让学生通过观察、类比、归纳,体会到在这类最值问题中,其实就是利用“两点之间线段最短”和“垂线段最短”这两个性质,再结合几何图形自身特点去解决问题,由此总结了这类问题的命题方向和解题规律,这也是本节课的重点和难点. Teaching practice, students often find the value of the graphics based on the most unfamiliar issues, this lesson by reviewing the “generals drink horses” model, to guide students to participate in knowledge review, and then put the model in the geometry, so that students Through observation, analogy and induction, I realized that in this type of most value problem, I actually use the two properties of “the shortest line segment between two points” and “the shortest vertical line segment”, and then combine the characteristics of the geometric figure Solve the problem, which sums up the proposition direction of these issues and the problem-solving law, which is also the focus of this lesson and difficulties.