Visualizing the Angle Between Two Planes

This GeoGebra example visualizes the dihedral angle between two intersecting planes in 3D space, showing how the angle is measured in a plane perpendicular to their line of intersection. The core mathematical concepts include spatial plane equations, normal vectors, the definition of the dihedral angle as the angle between two lines each perpendicular to the intersection line within the respective planes, and angle measurement in three dimensions. The construction uses GeoGebra commands such as Plane to define two planes p and q, IntersectPath to obtain their intersection line, Point and PointIn to place points on the planes, OrthogonalLine to construct lines perpendicular to the intersection, and Intersect and Angle to measure the angle α between the planes. Additional objects like lines, points, and parametric curves support dynamic visualization from multiple viewpoints. This resource is suitable for high school solid geometry or university analytic geometry courses, helping students grasp the concept of dihedral angles and spatial angle measurement through interactive exploration.