Square Pyramid as a Planar Graph

This example demonstrates how to represent a three-dimensional square pyramid (quadrilateral pyramid) as a planar graph, showing the topological structure of vertices, edges, and faces on a two-dimensional plane through projection or unfolding. Core mathematical concepts include solid geometry of pyramids, planar graph theory (vertices and edges), and basic properties of polygons and segments. Construction highlights: using GeoGebra commands such as Polygon to draw the base square and triangular side faces, Midpoint to construct auxiliary midpoints or the apex projection, and Segment to connect the apex to base vertices forming lateral edges. Multiple points (A to J) and segments (a to t) are used to build the complete planar network. This is suitable for upper secondary or early university students to understand the conversion between 3D solids and 2D representations, as well as applications of graph theory in geometry.