Rectangle Construction Exercise: Using Lines and Perpendiculars

① This example demonstrates how to construct a rectangle step by step using given lines and points, with perpendiculars and intersections, and then label its sides and angles. ② Core mathematical concepts include the definition of a rectangle (four right angles, opposite sides parallel and equal), the positional relationship between lines and perpendiculars, and the logical sequence in geometric construction. ③ Construction highlights: from the summary, commands such as Line, OrthogonalLine, Point, Intersect, Polygon, Segment, and Angle are used, with objects A, B, f, g, D, h, i, E, poly1, segments a, b, e, d, and angles α, β, γ, δ, showing a progression from basic elements to a complete figure. ④ Suitable for middle school geometry lessons or introductory geometric construction practice, helping students understand rectangle properties and master GeoGebra's basic construction tools.