In the figure, POS is a straight line. $\angle QOS = 138^\circ$ and $\angle POR = 130^\circ$. Find $\angle QOR$. Ans : ___ $^\circ$

1. Find $\angle POQ$ using angles on a straight line

Since $POS$ is a straight line, $\angle POQ + \angle QOS = 180^\circ$.
$\angle POQ = 180^\circ - 138^\circ = 42^\circ$

2. Find $\angle QOR$ by subtracting $\angle POQ$ from $\angle POR$

$\angle QOR = \angle POR - \angle POQ$
$\angle QOR = 130^\circ - 42^\circ = 88^\circ$