Triangle Orthocenter with Unit Circle Construction

This GeoGebra example demonstrates the geometric phenomenon that the three altitudes of a triangle intersect at a single point, the orthocenter H, while incorporating a unit circle to visualize relationships among the triangle's vertices, altitudes, and circumcircle. Core mathematical concepts include the orthocenter, altitudes, perpendicularity, unit circle, and angle measurement. The construction uses GeoGebra commands such as Circle, Point, Polygon, Angle, Line, OrthogonalLine, Intersect, Segment, and Ray to build triangle ABC, draw altitudes via orthogonal lines, find their intersection H, and add a unit circle with auxiliary segments. Suitable for middle school geometry or introductory college geometry courses, this interactive tool helps students grasp the orthocenter's properties and the concurrency of altitudes.