I.
Properties of triangles
01 Isosceles triangle
02 Circumcenter and incenter of a triangle

II.
Properties of a square
03 Parallelogram
04 Various squares

III.
Similarity of Figures and the Pythagorean Theorem
05 Similarity of shapes
06 Ratio of lengths of parallel lines and line segments
07 Center of gravity of a triangle
08 Pythagorean theorem

IV.
probability
09 Cases
10 probability