Construct a 45 Degree Angle

①This example demonstrates how to construct an exact 45-degree angle using geometric construction, a fundamental skill in classical geometry. ②The core mathematical concepts involve angle bisection, properties of isosceles right triangles, and perpendicular line construction—by bisecting a 90-degree right angle, one obtains a 45-degree angle. ③Construction details: based on the summary, the GeoGebra commands include Segment, with objects A, B, and line f; typically, one first draws segment AB, then constructs a perpendicular line, and finally uses a circle or angle bisector tool to mark the 45-degree angle. ④This is suitable for middle school geometry lessons or self-study, helping learners understand the logic and steps of compass-and-straightedge construction, and serving as a foundation for constructing more complex angles.