Perpendicular Line Construction 2

① This example demonstrates how to construct a line perpendicular to a given line through an external point, a classic geometric construction problem. ② The core mathematical concepts involve perpendicularity, uniqueness of the perpendicular, and rigorous geometric construction, including lines, points, and foot of perpendicular. ③ Construction details: Based on the summary, GeoGebra commands Line and PointIn are used, involving objects B, A, f, a, and P, where P is the external point; auxiliary lines or circles (possibly implicit) determine the foot, yielding the perpendicular line. ④ Suitable for middle school geometry lessons or introductory geometric construction, helping students understand the principle of perpendicular construction and basic GeoGebra tools.