Cbse Comprehension of lines and angles is critical in the study of geometry. Whether we know it or not, we see all sorts of angles on an everyday basis. The corners of a room, the way a ladder rests against a house, and the inclination of a hill all have angles that can be measured.

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