Constructing a Copy of an Angle with Compass and Straightedge (GeoGebra Included

This example demonstrates how to copy (construct) a given angle into a new angle that is congruent using compass-and-straightedge steps, and it extends the idea with activities focused on angle relationships and congruence—with and without GeoGebra. Key math concepts include geometric construction of angles, congruence of angles, and using circles (with a chosen radius) to locate intersection points that fix the copied rays. In the GeoGebra workflow, the construction is built from commands and objects such as Point (creating key points like the vertex and ray endpoints), PointIn/Intersect (finding required points constrained by the geometry), Segment (forming angle sides), Circle (drawing arcs centered at the vertex), and Angle/Ray (defining the angle and its rays). Additional logic such as Min and If helps manage radius/parameter selection and conditional steps. The activity is designed for interactive learning with sliders/animation (e.g., aniSli, aniMin/aniMax) and verification prompts (textInstr and related objects), making it well-suited for middle and high school geometry lessons on constructions and congruence.