Cross Sections of a Square Pyramid by Joseph Walsh

This GeoGebra example demonstrates how different planes intersect a square pyramid to create various polygonal cross-sections. Key mathematical concepts include: cross-section theory in solid geometry, calculation of intersection lines between spatial lines and planes, and properties of planar polygons. Construction points: Use the Pyramid command to construct square pyramid ABCD with vertex E; employ the Polygon command to draw pyramid faces (faceABE, faceBCE, etc.); utilize Intersect and IntersectPath commands to find intersections between planes and the pyramid, generating cross-section polygons; use Segment commands to draw pyramid edges. This example is suitable for high school solid geometry teaching, helping students understand how spatial cross-sections form and how different cutting positions produce varying cross-section shapes.