[教学内容]北师大版二年级下册第67耀68页[教材分析]“认识角”是在学生已经初步认识长方形、正方形的基础上学习的内容。角,作为几何图形的重要组成部分,认识角和角的组成是学习的重点内容。而通过直观感知,抽象出角的图形和比较角的大小,则是本节教学的难点所在。另外,学习这部分知识还为下节课学习角的分类打下基础。所以,应当在 [Teaching content] Beijing Normal University version of the second grade under the 67th chapter 68 [Textbook analysis] “Recognition angle ” is the students have been initially aware of the rectangular, square based on the learning content. Angle, as an important part of the geometry, the angle and angle of the composition is the focus of learning. Through the intuitive perception, the abstract figure of the corner and the comparison of the size of the corner, it is difficult to teach in this section. In addition, learning this part of the knowledge also laid the foundation for the classification of the next lesson learning angle. So, it should be