Orthocenter of a Triangle by Kurt Hoelsema

This example demonstrates how to construct the orthocenter of a triangle using GeoGebra. Key math concepts include perpendicular lines, intersection points, distance calculations, and geometric constructions. GeoGebra commands used are Distance, Line, OrthogonalLine, Intersect, with objects A, B, C, AB, AC, f, g, h, i, j, k, D. Suitable for high school mathematics education and geometric learning to understand orthocenter properties and construction methods.