北师大版九年级《数学》下册“直角三角形的边角关系”的第一节“从梯子的倾斜程度谈起”教学内涵丰富,通过对本节课的学习,学生能进一步体会比和比例、图形的相似、推理证明等数学知识之间的联系.同时,这节课也能为学生提供充分动脑思考、动手操作的机会,学生从中可以体会化归与转化、特殊到一般、数形结合的思想方法,并为后续学习锐角三角函数,利用锐角三角函数解直角三角形以及解决一些简单 Beijing Normal University’s edition of “Mathematics” in the ninth grade is the first section of the “angle relationship of the right triangle” “The inclination of the ladder ” is rich in teaching content. Through this lesson, students can further study. Comprehend the connection between mathematics, such as the ratio of learning and proportions, graphs, proof of reasoning, etc. At the same time, this class can also provide students with the opportunity to fully think brainstorming and hands-on operations, from which students can experience transformation and transformation, special to general. , a combination of number and shape thought methods, and follow-up learning acute angle trigonometric functions, use acute angle trigonometric functions to solve right angle triangles and solve some simple