Visualizing Interior and Exterior Angles

This example demonstrates how to construct and visually explore the relationship between interior and exterior angles at a vertex in a polygonal setting (often discussed via triangle cases). The main mathematical ideas include the definition of interior/exterior angles, measuring and comparing angles, and using geometric construction to maintain consistent angle placement so the relation becomes visually verifiable. Construction-wise, it leverages GeoGebra commands Polygon, Ray, Line, Angle, Intersect, and Mirror to build the figure and the angle annotations (key points such as A, B, C and labeled angles like α, β, γ, δ), using intersections to anchor rays/lines and mirror to obtain the corresponding exterior configuration. Suitable for middle/high-school geometry instruction, classroom demonstrations, and GeoGebra geometry construction practice.