Tricity Intersecting Planes: Constructing Intersections of Three Planes in 3D

This GeoGebra example demonstrates the geometric phenomenon of three planes intersecting in 3D space, showing how their common intersection point (or line) is determined. It covers core mathematical concepts such as plane equations in 3D coordinate geometry, intersection of planes, points and vectors, and spatial visualization. The construction uses GeoGebra commands: Polygon to create triangular plane faces, Point to define key vertices, and Intersect to compute intersection points between planes. Objects include points A, B, C, D, E, F, G, H, I, J, planes q1, q2, q3, and auxiliary lines a, b, c, d, e, f, g, h, i, j, which together build the intersecting structure step by step. This is suitable for high school or early university students learning solid geometry, spatial vectors, and plane equations, and also serves as a visual teaching aid for instructors explaining plane relationships in 3D.