Mathematics
Triangle
Concept of area of a plane figure. Area of a triangle
Height, and the median bisector of a triangle. Wonderful point of the triangle
Types of triangles
Cosine, sine, tangent and cotangent of an acute angle
Theorem of cosines and sine
Similarity of triangles
Interior and exterior angles of a triangle
Pythagoras' theorem
Thales' theorem. The middle line of the triangle
The relations between the sides and angles of a triangle
Signs of the triangle equality
Metric ratios in triangles