Preface Basic Geometry This book is intended to serve as a reference for the contents of Basic Geometry Disciplines taught in Elementary and Middle School. The content starts with the most basic definitions of point, line, and plane. Following it is presented the relationships between these elements showing all postulates. The third chapter introduces the triangles, all of its properties, postulates and theorems. The next chapter presents the Quadrilaterals, all its properties, postulates and theorems. The fifth chapter discusses the circumference and the circle, with all their properties, relationships and theorems. The sixth chapter is dedicated to polygons, its properties and construction. The seventh and final chapter shows ellipse, parabola and hyperbole curves, their construction and properties. The content contained in this book is basic to the next book on spatial geometry, which is the object of study in various disciplines at High School. Índice Chapter 1 Basic Elements of Plane Geometry Points, Lines and Planes Chapter 2 Point, Line and Plane Primitive Postulates of Plane Geometry Chapter 3 Triangles Definitions and Properties of Triangles Chapter 4 Quadrilaterals Definitions and properties of Quadrilaterals Chapter 5 Circumferences and Circles Definitions and Properties of Circumference and Circle Chapter 6 Polygons Polygons Concave and Convex Chapter 7 Conic Ellipse, Parabola, Hyperbola Ellipse Hyperbola Parabola