Postulate 1: Draw a Line Segment Through Two Points

① This example demonstrates Euclid's first postulate: through any two points, a unique straight line segment can be drawn, visualized in GeoGebra by constructing points A and B and connecting them with segment f. ② The core mathematical concept is the fundamental axiom of Euclidean geometry, involving points, lines, segments, and the property that two points determine a line, which underpins all subsequent geometric reasoning. ③ Construction highlights: from the summary, the Line command is used, with objects including points A, B, C, D, E and segment f; A and B are the key endpoints, while C, D, E may serve as auxiliary or labeling points, and segment f is generated by the Line command, illustrating direct geometric object construction via commands in GeoGebra. ④ Suitable for middle school geometry introduction, helping students grasp the intuitive meaning of postulates, for teachers demonstrating basic geometric construction operations, or as a simple example of programmatic geometric construction.