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

Estimated Time
30 minutes

Prerequisites/Instructions, prior preparations, if any
Prior knowledge of point, lines, angles

Materials/ Resources needed

 * Digital - Computer, geogebra application, projector.
 * Non digital -worksheet and pencil.
 * Geogebra files : “Linear pair axiom - ray on a line.ggb”

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


 * {| class="wikitable"


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