1.
Lines and Angles

2.
Lines
• A line is a collection of points going endlessly or at a fixed point in both
directions along a curved , straight or irregular path.
• Lines are divided into three
1. Lines ( itself )
2. Segment
3. Ray

3.
Lines , Segments , Rays
Lines
• A geometrical line extends endlessly in both directions
• Example = AB
• Example : Parallel lines ,Time , Universe????
A B

4.
Segments
• A geometric segment starts on one point and ends on the other
• Example = AB
• Example : Chalk , Pen , Spacebar in a keyboard
A B

5.
Rays
• A geometric Ray starts on one point and extends endlessly on the
other
• Example = AB
• Example : Sun rays ,Torch , Arrow
A B

6.
Angles
• An angle is the figure formed by two rays or line segments, called the sides of
the angle, sharing a common endpoint, called the vertex of the angle
• Angles are divided into six
1. Acute angle ( More than 0º less then 90º)
2. Right angle ( Exact 90º)
3. Obtuse angle ( More than 90º less than 180º)
4. Straight angle ( Exact 180º)
5. Reflex angle ( More than 180º less than 360º)
6. Complete angle ( Exact 360º)

7.
Angle
Acute angle Straight angle
Right angle Reflex angle
Obtuse angle Full angle

8.
Angles in real life