Elementary Operations in Geometry

This lecture covers elementary operations in geometry, including combinatorial cases, Thales' theorem, practical applications, proportionality, division, duplication, and multiplication of segments, as well as the power of a point relative to a circle. The instructor demonstrates the theorems and configurations related to angles, circles, and quadrilaterals, providing both Euclidean and modern proofs. The lecture also explores the concept of radical axis between two circles and the orthogonality of circles.