Observe the following picture. If the other angle of linear pair$=k°$, find $k$.

Observe the following picture. If the other angle of linear pair$=k°$, find $k$.

Observe the figure. There are two angles namely $\angle PQR = 150° \mathrm{and} \angle QPS = 30°$.  Is all this pair of supplementary angles a linear pair? Discuss. 

What would happen to the angles if we add $3$ or $4$ or $5$ rays on a line as given below? 

Can you justify the following statement.

$\angle AOB+\angle BOC+\angle COD+\angle DOE+\angle EOF+\angle FOA=360°?$

Four real life examples for vertically opposite angles are given below.

Give four more examples for vertically opposite angles in your surrounding.

In the given figure, two lines $\overleftrightarrow{AB}$ and $\overleftrightarrow{CD}$ intersect at $O$. Observe the pair of angles and complete the following table.

Name the two pairs of vertically opposite angles.

The value of $x$ in the given figure is _____$°$