This document provides information on orthographic projections and the projection of points and lines. It begins by outlining important notations used in orthographic projections. It then discusses the projection of points located in different quadrants and the simple cases of projecting lines, including vertical lines, lines parallel to planes, and inclined lines. The document also covers projections where the true length, views, or inclinations are known or unknown. It defines important parameters and diagrams the relationships between true length, views, and angles. Finally, it discusses problems involving the traces of lines on planes.