Current location - Training Enrollment Network - Mathematics courses - Junior high school mathematics knowledge point summary high frequency test site summary!
Junior high school mathematics knowledge point summary high frequency test site summary!
Summarizing the knowledge points of mathematics is very helpful for learning mathematics. Here I summarize the knowledge points of junior high school mathematics for your reference only.

Knowledge points of mathematical rational numbers

1. Classification of rational numbers: rational numbers include integers and fractions, integers include positive integers, 0 and negative integers, and fractions include positive and negative fractions. "Classification" principle: (1) proportionality (no weight, no leakage); (2) There are standards.

2. Non-negative number: the collective name of positive number and zero.

3, the opposite number:

(1) Definition: If the sum of two numbers is 0, the two numbers are opposite.

(2) Formula for finding the inverse number: the inverse number of A is-A. ..

(3) Properties: ① When a ≠ 0, A ≠-A;

② The positions of A and -a on the number axis are symmetrical about the origin;

③ The sum of two opposites is 0 and the quotient is-1.

Junior high school similar triangles kaodian

Test center: similar triangles's concept, the meaning of similarity ratio, and the enlargement and reduction of drawing graphics.

Assessment requirements: (1) Understand the concept of similarity; (2) Grasping the characteristics of similar figures and the significance of similarity ratio, we can enlarge and reduce the known figures as needed.

Test sites: the proportion theorem of parallel lines and the related theorem of parallel lines on one side of a triangle.

Examination requirements: Use the proportional theorem of parallel lines to understand and solve some geometric proofs and geometric calculations.

Note: An edge judged to be parallel cannot be used as the corresponding line segment in the condition in proportion.

Test site: similar triangles's concept

Evaluation requirements: Based on the concept of similar triangles, master the characteristics of similar triangles and understand the definition of similar triangles.

Knowledge points of mathematical symmetric graphics

Axisymmetric graphics: line segment, angle, isosceles triangle, equilateral triangle, diamond, rectangle, square, isosceles trapezoid and circle.

Number of symmetry axes: an angle has a symmetry axis, that is, the angle bisector of the angle; The isosceles triangle has an axis of symmetry, which is the median vertical line of the base; An equilateral triangle has three axes of symmetry, that is, the median vertical lines on three sides; A diamond has two symmetry axes, which are straight lines where two diagonals are located, and a rectangle has two symmetry axes, which are straight lines between two groups of opposite sides.

Centrally symmetric figures: line segments, parallelograms, diamonds, rectangles, squares and circles.

Symmetry center: the symmetry center of the line segment is the midpoint of the line segment; The symmetrical center of parallelogram, rhombus, rectangle and square is the intersection of diagonal lines, and the symmetrical center of circle is the center of circle.

Description: Line segments, diamonds, rectangles, squares and circles are all symmetrical figures.

The above is my summary of junior high school mathematics knowledge points for your reference only, and I hope it will help you.