Current location - Training Enrollment Network - Mathematics courses - Arrangement of knowledge points in the second volume of ninth grade mathematics
Arrangement of knowledge points in the second volume of ninth grade mathematics
The application of circle in the field of mathematics is very extensive and universal. The following is the knowledge point arrangement of the second volume of ninth grade mathematics that I brought to you, hoping to help you!

Arrangement of "circle" knowledge points in the second volume of ninth grade mathematics

Chapter 10 Circle

★ Key points ① Important properties of the circle; (2) the positional relationship between straight lines and circles, and between circles; ③ Angle theorem related to circle; ④ Theorem of proportional line segment related to circle.

☆ Summary ☆

First, the basic properties of the circle

Definition of 1. circle (two kinds)

2. Related concepts: chord and diameter; Arc, equal arc, upper arc, lower arc, semicircle; Distance from chord to center; Equal circle, same circle, concentric circle.

3. "Three-point circle" theorem

4. Vertical Diameter Theorem and Its Inference

5. "Equivalence" theorem and its inference

5. Angle related to circle: (1) Definition of central angle (equivalence theorem)

(2) the definition of the angle of circle (the theorem of the angle of circle, the relationship with the angle of center)

⑶ Definition of chord angle (chord angle theorem)

Second, the positional relationship between a straight line and a circle

1. Three positions and their judgments and properties:

Review outline of junior high school mathematics

2. The nature of the tangent (key point)

3. Judgment theorem of tangent (key point). What is the determination of the tangent of the circle (1)? ⑵?

4. Tangent length theorem

Third, the position relationship between circles.

Review outline of junior high school mathematics 1. Five positional relationships and their judgments and properties: (emphasis: tangency)

2. The property theorem of the tangent (intersection line) connecting two circles.

3. Common tangent of two circles: (1) Definition (2) Property

Four, proportional line segment related to the circle

Review outline of junior high school mathematics 1. the intersection string theorem

2. Cutting line theorem

Verb (abbreviation for verb) and regular polygon

The inscribed and circumscribed polygons of 1. circle (triangle, quadrilateral)

2. The circumscribed circle, inscribed circle and properties of triangle.

3. The properties of circumscribed quadrangles and inscribed quadrangles of a circle

4. Regular polygon and its calculation

Central corner: review outline of junior high school mathematics

Half of the Inner Corner: Review Outline of Junior High School Mathematics (right)

(Solve Rt△OAM to find out the relevant elements, junior high school mathematics review outline, junior high school mathematics review outline, etc. )

Six, a set of calculation formulas

1. circumference formula

2. Formula of circular area

3. Sector area formula

Review outline of junior high school mathematics 4. Arc length formula

5. Calculation method of arch area

6. The side development diagram of cylinder and cone and related calculation.

Seven, the trajectory of the point

Six basic trajectories

Eight, drawings.

1. Draw the circumscribed circle and inscribed circle of the triangle.

2. Divide known arcs equally

3. Find the median ratio of two known line segments.

4. Equal circumference: 4, 8; 6, 3 equal parts

Nine, the basic graphics

Important auxiliary line

1. Production radius

2. Chords are usually regarded as the distance from the center of the chord.

3. See the diameter is usually used as the circumferential angle on the diameter.

4. Don't forget to connect the center of the tangent point

5. Common tangent of two circles (connecting line)

6. Two circles intersect a common chord.