Question

Fill in the blanks :

A linear pair is a pair of adjacent angles whose _________ sides are opposite rays.

Answer 1

Linear pair :

A pair of adjacent angles, whose non-common sides are opposite rays, is known as linear pair. Angles in a linear pair are supplementary (their sum is $180°$)

In the given figure the sum of $\angle AOB$ and $\angle COB$ is $180°$ (i.e. $40°+140°=180°$)

So, $\angle AOB$ and $\angle COB$ are adjacent supplementary angles and rays $\overrightarrow{OA}$ and $\overrightarrow{OC}$are the non-common opposite rays.

Hence a linear pair is a pair of adjacent angles whose non - common sides are opposite rays.