The second and third years of junior high school total review math focus, formulas, thank you

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A complete set of theorems in junior high school.

1. There is only one straight line after two points.

2. The shortest line segment between two points.

3. The complementary angles of the same angle or equal angle are equal.

4. The co-angle of the same angle or equal angle is equal.

5. There is only one and only one straight line perpendicular to the known straight line.

6. Among all the line segments connected by the points outside the line and each point on the line, the perpendicular line segment is the shortest.

7. The axiom of parallelism passes a point outside the straight line, and there is only one straight line parallel to the straight line.

8. If both lines are parallel to the third line, the two lines are also parallel to each other.

9. The same angle of the lifting school is equal, and the two straight lines are parallel.

10. The internal wrong angle is equal, and the two straight lines are parallel.

11. The inner angles of the same side are complementary, and the two straight lines are parallel.

12. The two straight lines are parallel and the isotopic angles are equal.

13. The two straight lines are parallel, and the internal wrong angles are equal.

14. The two straight lines are parallel and complementary to the inner angles of the same side.

15. Theorem The sum of the two sides of the triangle is greater than the third side.

Middle School Math Formulas.

Basic properties of proportions:

If a:b=c:d, then ad=bc

If ad=bc, then a:b=c:d

2) Proportional properties:

If a b = c d, then (a b) b = (c d) d

3) Proportional properties:

If a b=c d=....=m/n(b+d+…+n≠0), then (a+c+....+m)/(b+d+…+n)=a/b

The median line of the trapezoidal line theorem is parallel to the two bases and is equal to half of the sum of the two bases l=(a+b) 2s=l h

Rhombus area = half of the diagonal product, i.e. s = (a b) 2

Parallel lines divide line segments proportionality theoremThree parallel lines cut two straight lines, and the corresponding line segments obtained are proportional.

Summary of key knowledge points in mathematics.

A circle is a set of points whose distance from a fixed point is equal to that of a fixed length.

The inside of a circle can be thought of as a collection of points whose center is less than the radius.

The outer part of a circle can be seen as a collection of points whose distance from the center of the circle is greater than the radius.

The radius of the same circle or equal circle is equal.

The trajectory of a point whose distance to a fixed point is equal to a fixed length is a circle with a fixed point as the center and a fixed length as the radius.

The trajectory of a point at the same distance from the two endpoints of a known line segment is a perpendicular bisector of the line segment.

The trajectory to a point of equal distance on both sides of a known angle is the bisector of that angle.

A trajectory to a point where two parallel lines are at equal distances is a straight line parallel to the two parallel lines at equal distances.

The decision theorem of tangents passes through the outer end of the radius and a straight line perpendicular to this radius is a tangent of a circle.

Function learning verbal decision.

The proportional function is a straight line, the image must pass the silver dot, the positive and negative of k is the key, which determines the quadrant of the straight line, the negative k goes through two or four limits, x increases y and decreases, and the up and down translation k remains unchanged, and the line is obtained by the lead, and b is added up and subtracted downward, the image passes through three limits, and two points determine a line, and the selection coefficient is the key.

The inverse proportional function hyperbola, only one point is needed to be determined, the positive k falls in one or three limits, x increases and y decreases, any point on the image, the area of the rectangle remains the same, and the axis of symmetry is the order of the angular divider x and y can be exchanged.

The quadratic function parabola, the selection needs three points, the positive and negative opening judgment of A, the size of C on the y-axis, the symbol is the simplest, the number of intersection points on the X-axis, the food poisoning knot of B is fully calculated, the parabola translation on the left side of the axis of the same sign A and B does not change, the vertex leads the image to rotate, the three forms can be transformed, and the matching method plays the most critical role.

Similar triangle knowledge points.

Test points: the concept of similar triangles, the meaning of similarity ratios, and the enlargement and reduction of drawing figures.

Assessment requirements: (1) understand the concept of similarity; (2) Master the characteristics of similar graphics and the significance of similar ratios, and be able to enlarge and reduce known graphics according to requirements.

Test points: theorem of proportionality of parallel lines and parallel lines on one side of a triangle.

Assessment requirements: Understand and use the proportionality theorem of parallel lines and line segments to solve some geometric proofs and geometric calculations.

Note: The side that is judged to be parallel cannot be used proportionally as the corresponding line segment in the condition.

Test point: The concept of similar triangles.

Assessment requirements: Based on the concept of similar triangles, grasp the characteristics of similar triangles and understand the definition of similar triangles.

Cross a three-point circle.

1. Cross a three-point circle.

Three points that are not on the same line determine a circle.

2. The circumscribed circle of the triangle.

The circle that passes through the three vertices of the triangle is called the circumscribed circle of the triangle.

3. The outer center of the triangle.

The center of the circumscribed circle of the triangle is the intersection of the perpendicular bisector of the three sides of the triangle, which is called the outer center of the triangle.

4. The nature of the quadrilateral inside the circle (the judgment condition of the four-point common circle).

The circle is surrounded by quadrilaterals and complements each other diagonally.

1. Basic requirements for mathematics review.

The content of mathematics review can be divided into two parts: basic knowledge and basic problem-solving skills. In the review, it is necessary to pay attention to the analysis, comparison and flexible application of basic concepts, basic formulas, basic laws and laws, so as to understand, synthesize and innovate.

The so-called "understanding" is to strive to integrate the basic knowledge and basic concepts of mathematics learned in middle school from part to whole, from micro to macro, from concrete to abstract from multiple angles, at multiple levels, and in an all-round way, and consciously cultivate one's ability to analyze and understand, comprehensively generalize, and abstract thinking. For the review of definitions, theorems, and formulas, it should be done to: figure out the ins and outs, communicate the interrelationships, master the process of deduction, pay attention to the form of expression, summarize the memory methods, and clarify the main uses.

The so-called "synthesis" refers to the refinement and processing of the mathematical knowledge learned in different disciplines, different units, different grades, and different times, from the surface to the inside, and from the shallow to the deep, so as to establish the vertical and horizontal connections between knowledge, so that the knowledge is systematic, organized, and networked, easy to remember, easy to store, and easy to extract and apply. For example, to review the concept of angles, you can summarize them as follows:

1) The angle formed by the coplanar straight line - the angle formed by the straight line and the plane - the angle formed by the plane and the plane is clarified, so as to understand the formation and development of this essential, how the former is expanded to the latter, and how the latter is transformed into the former to solve.

2) Analogous differences between inclination angles, radial angles, and polar angles, so that the concept of angles is clearer and more accurate.

3) In the triangle: the expression forms and characteristics of the same angle, horizontal angle, vertical angle, quadrant angle, interval angle, azimuth angle and other terminal angles, and the application rules and methods are sorted out.

The so-called "innovation" refers to the flexibility, originality, simplicity, criticality and profundity shown in the process of solving problems after integrating basic knowledge. The ability to innovate is not only manifested in the comprehensive use of the knowledge learned to analyze and solve problems, but more importantly, to discover new problems, broaden and deepen the field of knowledge learned, and constantly enhance their adaptability. To this end, each student should pay attention to discovering and digging out the problems that are not in the books and not covered by the teacher according to the knowledge they have learned.

For example, understanding the multiple connotations of a concept, thinking about a problem from different angles (i.e., multiple solutions to one problem), summarizing the rules of solving common problems (i.e., multiple problems and one solution), and discovering ways to solve problems.