Junior high school mathematics theorem formula 1, point, line and angle
Theorem of points: there is only one straight line passing through two points.
Point theorem: the shortest line segment between two points.
Angle theorem: the complementary angles of the same angle or equal angle are equal.
Angle theorem: the complementary angles of the same angle or equal angle are equal.
Straight line theorem: there is only one straight line perpendicular to the known straight line at one point.
Straight line theorem: Of all the line segments connecting a point outside a straight line with a point on a straight line, the vertical line segment is the shortest.
2. Geometric parallelism
Parallelism theorem: after passing a point outside a straight line, there is one and only one straight line parallel to this straight line.
Inference: If both lines are parallel to the third line, then the two lines are also parallel to each other.
Prove the parallel theorem of two straight lines: the same angle is equal and the two straight lines are parallel; Internal dislocation angles are equal and two straight lines are parallel; The internal angles on the same side are complementary and the two straight lines are parallel.
Inference that two straight lines are parallel: two straight lines are parallel and the same angle is equal; The two straight lines are parallel and the internal dislocation angles are equal; These two lines are parallel and complementary.
3. Triangle Interior Angle Theorem
Theorem: The sum of two sides of a triangle is greater than the third side.
Inference: The difference between two sides of a triangle is smaller than the third side.
Theorem of sum of interior angles of triangle: the sum of three interior angles of triangle is equal to 180.
Congruent triangles decided.
Theorem: The sides and angles corresponding to congruent triangles are equal.
Edge Theorem (SAS): Two triangles have two sides, and their included angles are congruent.
Angle Theorem (ASA): Two triangles have two angles and their sides are congruent.
Inference (AAS): Two triangles with two angles and opposite sides of one angle are congruent.
Edge Theorem (SSS): Two triangles corresponding to three equilateral sides are congruent.
Hypotenuse and right-angled edge theorem (HL): Two right-angled triangles with hypotenuse and a right-angled edge are congruent.
Methods and skills to improve junior high school math scores; Comprehensive memory.
The definition, rules, formulas and theorems of junior high school mathematics should be remembered, and those that you don't understand for the time being should be remembered. On the basis of memory, we should deepen our understanding when applying them to solve problems. For example, mathematical definitions, rules, formulas and theorems are just like axes, saws, Mo Dou and planers in the hands of carpenters. Without these tools, carpenters can't make furniture.
practise
Proper practice is necessary. Finally, I returned to this traditional topic-doing problems. If you want to learn math well, it is impossible not to do the problem. Doing problems can help us deepen our understanding of knowledge points, improve the speed of solving problems, and be skilled in solving problems.