Rotation Matrix Demo

This example demonstrates the graphical transformation of a triangle in a 2D plane under the action of a rotation matrix. Key mathematical concepts include rotation matrices, linear transformations, geometric transformations, vectors, and coordinate geometry. The construction utilizes GeoGebra commands such as Polygon, ApplyMatrix, angle θ, vertices A/B/C, polygon objects poly1/poly1', rotation matrix M, transformed vertices A'/B'/C', text annotations text1/text2, and auxiliary objects u/v/u'/v'. It is suitable for high school and university students studying linear algebra, geometric transformations, and matrix applications, as well as for introductory university mathematics teaching demonstrations.