1. Introduction to Lines and Angles

INTRODUCTION 
1.    Point: 
      A fine dot made by a sharp pencil or a geometrical figure having no length, breadth and height as called a point.

2.    Line segment
      If we join two fixed points then the figure formed is called line segment.

3.    Line
      If we extend the two end points of a line segment in either direction endlessly then it is called a line.
      It has no definite length.

4.    Ray
      If we extend one end point of a line segment endlessly then it is called a ray.

5.    Angle
      An angle is formed by intersecting two rays. The intersection point is the common initial point of these two rays which is called as vertex of the angle. We use the symbol ‘ ∠’ to denote the measure of the angle
    •    An angle is an inclination between two rays with the same initial point.

In this fig. the angles are  ∠∠

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