Exploring Angle Properties of Triangles

This GeoGebra example demonstrates the angle properties of triangles through an interactive geometric construction in which students formulate and answer their own questions. Core mathematical concepts include the triangle angle-sum theorem, exterior angle relationships, angle measurement, and polygonal geometry. The construction uses GeoGebra commands such as Polygon to build triangles (poly1, poly2, poly3), Angle to label and measure angles (α, β, α₁, δ, ε, ζ, etc.), Circle (c), Point (A, B, C, D, E, F, J, K, L, M, etc.), Segment, and Ray, supplemented by text object text4 for instructions or results. It is suitable for middle school geometry classes (grades 7–9) and high school review, supporting inquiry-based learning and formative assessment.