The 20 1 1 version of mathematics curriculum standard divides the curriculum content into four parts, namely, number and algebra, figure and geometry, statistics and probability, synthesis and application. Graphics and geometry are divided into four categories, namely, the cognition and measurement of graphics, the movement of graphics and the position of graphics. Today, the acute angle and oblique angle written by Ma Qingqun, a middle school student in Beimeng, and Hu, a middle school student in Pengkou, belong to "graphic understanding". Today, I will talk to you about some problems that should be paid attention to in the teaching of graphic geometry.

First of all, let students perceive the characteristics of graphics in their life situations.

"Mathematics Curriculum Standard" emphasizes the connection between mathematics and real life, and points out in the teaching objectives: understanding mathematics knowledge, the connection between mathematics and other disciplines, and mathematics and life. Therefore, it is required that not only the selection of materials must be closely related to students' real life, but also mathematics teaching must start with students' familiar life situations and interesting things to provide students with opportunities for observation and operation. In teaching, we try to link classroom teaching with real life and create life situations in mathematics teaching, so that students can experience and understand mathematics in real situations and feel the happiness brought by mathematics.

Psychological research shows that the closer the learning content is to the life reality that students are familiar with, the higher the degree of students' conscious acceptance of knowledge. According to this feature, before teaching the new curriculum content, we usually borrow relevant life examples to create situations related to the teaching content for students and ask relevant questions, so as to arouse students' curiosity and thinking and stimulate students' interest in learning and thirst for knowledge.

For example, today, teachers in these two classes can introduce perspectives from their lives. In particular, Mr. Hu attaches great importance to let students find acute angle, obtuse angle and right angle in class, and let students realize that mathematics is useful and mathematics is around.

The creation of this life situation has stimulated students' desire to show their achievements, and they are more active in their studies. Starting from the reality of students' life, introducing new courses not only makes students feel that mathematics is everywhere, but also enhances their confidence in understanding and applying mathematics, and at the same time strongly stimulates students' interest and arouses their enthusiasm for learning.

Second, let students gain graphic knowledge through active participation.

Curriculum standards clearly point out in the basic concept of curriculum: "Students' learning should be a lively, proactive and personalized process. Listening carefully, thinking actively, practicing, exploring independently and cooperating are all important ways to learn mathematics. The lesson "Acute Angle and Oblique Angle" is to further expand the extension of angles and classify them on the basis that students have learned how to recognize angles and right angles, so that students can fully perceive acute angles and obtuse angles. From the cognitive level, it is not difficult for students to know which are acute angles and which are obtuse angles. However, it is difficult to explore why it should be classified and how to operate. On this basis, it is worth considering for students to think more deeply. It is difficult for students to correctly judge the obtuse angle greater than the right angle and the acute angle less than the right angle only by observation. This is the right angle in the comparison triangle. How can students compare it by hand? Today, the teaching of these two courses is not in place at this point, but the teachers have done more or demonstrated it with the media.