This lecture covers the definition and properties of the scalar product in R^2 and R^3, including symmetry, distributivity, and positivity. It explains how to calculate the length of a vector, the angle between two vectors, and how to use the scalar product to compute these. The lecture also introduces the concept of the norm of a vector and its calculation. Additionally, it discusses the application of rotations to calculate the scalar product and angles between vectors in 2D and 3D spaces.