Common junior high school mathematics formulas
1. There is only one straight line between 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 complementary angles of the same angle or equal angle are equal.
5. There is one and only one straight line perpendicular to the known straight line.
6. Of all the line segments connecting a point outside the straight line with points on the straight line, the vertical line segment is the shortest.
7. The axiom of parallelism passes through a point outside a straight line, and one and only one straight line is parallel to this straight line.
8. If two straight lines are parallel to the third straight line, the two straight lines are also parallel to each other.
9. The same angle is equal and two straight lines are parallel.
10. The internal dislocation angles are equal and the two straight lines are parallel.
1 1. The inner angles on the same side are complementary and the two straight lines are parallel.
12. Two straight lines are parallel and have the same angle.
13. Two straight lines are parallel and the internal dislocation angles are equal.
14. Two straight lines are parallel and complementary.
15. Theorem The sum of two sides of a triangle is greater than the third side.
16. Inference that the difference between two sides of a triangle is smaller than the third side.
17. The theorem of triangle interior angle sum is equal to 180?
18. It is inferred that the two acute angles of 1 right triangle are complementary.
19. Inference 2 An outer angle of a triangle is equal to the sum of two non-adjacent inner angles.
20. Inference 3 The outer angle of a triangle is larger than any inner angle that is not adjacent to it.
2 1. congruent triangles has equal sides and angles.
22. The Axiom of Angle and Edge (SAS) has the consistency of two triangles with equal included angles on both sides.
23. The corner axiom (ASA) has two corners and two triangles with equal corresponding sides.
24. Reasoning (AAS) has two angles, and the opposite side of one angle corresponds to the congruence of two triangles.
25. The side-by-side axiom (SSS) has three sides, corresponding to the coincidence of two triangles.
26. The axiom of hypotenuse and right-angled side (HL) has a hypotenuse and a right-angled side corresponding to the coincidence of two right-angled triangles.
27. Theorem 1 The distance from the point on the bisector of the angle to both sides of the angle is equal.
28. Theorem 2 The point where two sides of an angle are equidistant is on the bisector of this angle.
29. The bisector of an angle is a collection of all points with equal distance to both sides of the angle.
30. The nature theorem of isosceles triangle The two bottom angles of isosceles triangle are equal (that is, equilateral and equilateral).
3 1. Inference 1 The bisector of the vertices of an isosceles triangle bisects the base and is perpendicular to the base.
32. The bisector of the top angle, the median line on the bottom edge and the height on the bottom edge of the isosceles triangle coincide with each other.
33. Inference 3 All angles of an equilateral triangle are equal, and each angle is equal to 60?
34. Decision theorem of isosceles triangle If a triangle has two equal angles, then the sides of the two angles are also equal (equal angles and equal sides).
35. Inference 1 A triangle with three equal angles is an equilateral triangle.
36. Inference 2 has an angle equal to 60? An isosceles triangle is an equilateral triangle.
37. In a right triangle, if an acute angle equals 30? Then the right angle it faces is equal to half of the hypotenuse.
38. The median line on the hypotenuse of a right triangle is equal to half of the hypotenuse.
39. Theorem The point on the vertical line of a line segment is equal to the distance between the two endpoints of this line segment.
40. The inverse theorem and the equidistant point between the two endpoints of a line segment are on the vertical line of this line segment.
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