General review of mathematics in senior high school entrance examination
Guiding Draft of Basic Understanding of Circle
First, create situations to introduce new lessons.
Arrange some pictures to enjoy and introduce the review content of this section.
Second, the main content analysis of this chapter
Third, the test center analysis
1, test content: ① Understand the circle and its related concepts, understand the relationship between arc, chord and central angle, and understand the positional relationship between point and circle, straight line and circle, and circle and circle.
(2) Understand the nature of the circle, the relationship between the fillet and the central angle, and the characteristics of the diameter to the fillet.
③ Understand the inner and outer centers of triangles.
④ Understand the concept of tangent and the relationship between tangent and tangent radius; It can be judged whether a straight line is the tangent of a circle, and the tangent of the circle will be drawn through a point on the circle.
⑤ The arc length and sector area can be calculated, and the lateral area and total area of the cone can be calculated.
2. Test center comments: The focus of the middle school entrance examination is the angle related to the circle, and the correlation solution mainly examines the vertical diameter theorem and the similarity (line segment ratio) of the triangle.
3. Examination questions: This part of the questions is flexible and accounts for a large proportion of the examination questions in various places over the years. As far as the form of examination is concerned, it can be examined separately, and it is often combined with the knowledge of geometry, equations and functions in the previous chapters.
Fourth, review the test sites
1. A circle is a centrally symmetric figure with a symmetric center, and a circle is also a figure.
Is its axis of symmetry.
Related concepts of circle
1. A graph composed of all points whose distance from a plane to a fixed point is equal to a fixed length is called a circle. Where the fixed point is called. ......