Main Concepts And Results
- A line segment corresponds to the shortest distance between two points.
- The line segment joining points A and B is denoted as AB or as BA.
- A ray with initial point A and a point B on it is denoted as AB Line AB is denoted as AB
- Two distinct lines in a plane that cross at a point are called intersecting lines, otherwise they are called parallel lines.
- Two rays with a common initial point form an angle.
- A simple closed curve made of line segments only is called a polygon.
- A polygon of three sides is called a triangle and that of four sides is called a quadrilateral.
- A polygon with all its sides equal and all its angles equal is called a regular polygon.
- A figure, every point of which is equidistant from a fixed point is called a circle.
- The fixed point is called its centre and the equal distance is called its radius.