Exploring Interior Angle Sums of Convex Polygons

① This interactive GeoGebra activity dynamically constructs a convex polygon and allows students to explore how the sum of its interior angles changes with the number of sides. ② Core mathematical concepts include the interior angle sum theorem for convex polygons ((n-2)×180°), the relationship between side count and angle sum, and the method of triangulating a polygon to derive the formula. ③ Construction highlights: using the Polygon command to create vertices A, B, C, D, E, F forming poly1, with sides a, b, c, d, e, f automatically generated; students can drag vertices to reshape the polygon and observe that the angle sum remains constant for a fixed number of sides, while also using a spreadsheet to record angle sums for different polygon types. ④ Suitable for middle school geometry classes or high school review sessions, especially for pair work that combines data collection with inductive reasoning to foster general mathematical thinking.