Bentley Triangle Orthocenter Construction

①This example demonstrates how to construct the orthocenter of a triangle named 'Bentley Triangle' using geometric construction, showing the intersection of its three altitudes. ②The core mathematical concept is the orthocenter of a triangle (the common intersection point of the three altitudes), involving basic elements such as polygons, lines, perpendicular lines, intersection points, and angles. ③Construction details: Based on the construction summary, it uses GeoGebra commands including Polygon to create the triangle, Line to draw sides, OrthogonalLine to construct altitudes, Intersect to find the orthocenter, and Angle to mark relevant angles; objects include vertices A, B, D, polygon poly1, sides a, side_2, d, sides, side_1, side, altitudes altitude_1, altitude_2, altitude, orthocenter, and angles α, β, γ. ④This is suitable for middle or high school geometry lessons or introductory geometric construction practice, helping students intuitively understand the existence and uniqueness of the orthocenter and practice using GeoGebra's basic construction tools.