Types of Angle

1. Acute Angle:  Greater than 0° but less than 90° .0°<Acute Angle>90°.
                          
   
2. Right Angle: Equal to 90°.
   
   
   
     
   
   
   
   
   
3.  Obtuse Angle:Greater than 90° but less than 180°.90°<Obtuse Angle>180°   
   
4. Straight Angle: Equal to 180°.
   
5. Reflex Angle: Greater than 180° but less than 360°.    
   
   
                                                              
   
                                              180°<Reflex Angle>360°                                     Reflex Angle = 360° - Interior Angle                                                                                              = 360° - 49°  = 311° 
6.                   

Angles

  When two rays are originated from same points an angle is formed.

The corner point  "C" is called vertex.The rays CA and CB making an angle .Where CA and CB are called arms. 

Angle is denoted by a symbol <ACB.

Collinear and non-Collinear Points

If  three or more points lie on the same line they are called collinear points otherwise they are called non-collinear points.

here P, Q and R are collinear points and X,Y and Z are none collinear points.

LINES

                                    

• A line is always straight.
• A line has no thickness.
• A line is extended in both directions.
• A line has no ends.
• When a line has one end it's called a  "RAY".                                                                                                                           
                        
  
• Example of  ray is torch .Which have one end.                                                                             
• When a line has two ends it's called a "Line Segment".Figure have two ends "A" and "B".                                     
•  Lines can be two types either Intersecting Lines and Non-Intersecting or Parallel.