# Linear pair axiom : If a ray stands on a line, then the sum of two adjacent angles so formed is 180 degrees

Two adjacent angles are said to be form a linear pair of angles, if their non-common arms are two opposite rays. Linear pair axiom of theorems are if a ray stands on a line , then the sum of two adjacent angles so formed is 180 degree

### Objectives

Introduce children to linear pair of angles

30 minutes

### Prerequisites/Instructions, prior preparations, if any

Prior knowledge of point, lines, angles

### Process (How to do the activity)

• Prior hands on activity
• Start with coinciding point C with the point B
• What is the angle formed by the line
• Move point C above and slowly rotate around point 0
• How many angles do you notice
• Name the angles formed : what are their measure
• Do the two angles together form a 180o angle
• Do the two angles form a linear pair
• Record the values of the two angles for various positions of point C

 Sl No. ∠BOA ∠BOC ∠COA ∠BOC + ∠COA Dothe angles form a linear pair .
• Evaluation at the end of the activity