1. Definition of parallel lines and properties of triangles and quadrilaterals

2. Misalignment of triangles

2.1 Water depth
2.2 Circumcenter
2.3 Inwardly
2.4 Carelessness
2.5 Center of gravity of a triangle

3. Similar triangles

3.1 Definition
3.2 Similarity to right triangles

4. The theorem of Menelaus and Cheba

4.1 Conditions for three points to lie on a straight line
4.2 Conditions for three straight lines to meet at one point

5. Area of ​​a plane figure

6. Pythagorean Steward Pappus's theorem

7. Properties of circles, butterfly theorem, Ptolemy theorem, Simpson's theorem

7.1 Sizes of circles and angles
7.2 Properties of circles and tangents
7.3 Similar to a circle
7.4 Proportion to the circle
7.5 Park Point
7.6 Ptolemy's theorem
7.7 Butterfly Theorem
7.8 Simpson's Theorem

8. Trigonometry and Geometry

8.1 Ratios of the lengths of the three sides of important right triangles
8.2 Sine Law
8.3 Cosine's Second Law
8.4 Area of ​​a triangle
8.5 Various Operational Rules of Trigonometric Functions

9. KMO Math Contest Geometry Solution Book