This document provides an overview of key concepts in plane geometry covered in Chapter 5, including points, lines, planes, angles, parallel and perpendicular lines, triangles, polygons, coordinate geometry, congruence, transformations, and tessellations. Specific topics discussed include classifying angles, properties of parallel lines cut by a transversal, the triangle sum theorem, types of triangles and polygons, finding total angle measures of polygons, and using coordinate geometry. Homework problems are provided at the end of sections for additional practice.