Unit 4: Altitudes and Orthocenter

This GeoGebra example demonstrates the orthocenter, the intersection point of the three altitudes of a triangle. It visually explores the core concept that the altitudes of a triangle are concurrent, and how the orthocenter's position varies with triangle type: inside for acute triangles, at the right-angle vertex for right triangles, and outside for obtuse triangles. The construction likely uses line tools to draw perpendiculars from each vertex to the opposite side, and intersection tools to mark the orthocenter. Additional elements such as a kite and secant lines may be included to illustrate related properties or connections. This resource is suitable for high school geometry or introductory college geometry courses, helping students grasp the properties of the orthocenter and enabling dynamic exploration of its locus as vertices move.