Task 1B: Trapezoid Inscribed in a Semicircle and Interior Angles

① This example demonstrates the construction of a trapezoid inscribed in a semicircle and the investigation of its interior angles. ② Core mathematical concepts include semicircles, inscribed polygons, trapezoid properties, the interior angle sum theorem, and the application of linear regression and power functions in data analysis. ③ Construction details: using GeoGebra commands such as Intersect to find intersection points, Semicircle to draw the semicircle, Point to define vertices, Polygon to construct the trapezoid, and InteriorAngles to measure angles; objects include points A, B, C, semicircle c, trapezoid t1, sides a, b, c_1, and angles α, β, γ. ④ Suitable for middle school geometry lessons or math lab activities, allowing students to visually explore properties of cyclic quadrilaterals, drag vertices to observe angle changes, and use statistical tools to analyze data patterns.