This document defines key geometric terms like point, line, plane, segment, ray, and intersection. It provides examples of undefined terms like points, lines and planes. Defined terms include segments, rays, and opposite rays. The document explains that two or more figures intersect if they share at least one common point, and the intersection is the set of shared points. Examples demonstrate intersections between lines and planes, including lines within a plane, not intersecting a plane, or intersecting at a single point. Homework problems are assigned from the textbook.