This document defines and describes several basic geometric shapes and concepts. It defines a point as having no size, a line as extending infinitely in both directions with no thickness, a line segment as having two endpoints and a fixed length, a ray as having one endpoint and extending infinitely in one direction, and an angle as being formed by two rays meeting at a common point. It also defines parallel lines as never intersecting and having a constant distance between them, perpendicular lines as intersecting at a right angle, and concurrent lines as passing through a single common point.