Question

In the given figure, if $PQ\parallel RS$, then the valueof $\angle QSR$ is equal to:

• A. ${100}^o$
• B. ${120}^o$
• C. ${70}^o$
• D. ${60}^o$

Answer 1

The correct option is B ${120}^o$

In figure given $PQ||RS$ and $\angle PQS={60}^0$ and $\angle QEF={30}^0$

The $PQ||RS$ and line $QSE$ meet it then

$\angle PQS=\angle RSE={60}^0$

The line QSE is a straight line then

$\angle QSR+\angle RSE={180}^0$

$\Rightarrow \angle QSR+{60}^0={180}^0$

$\Rightarrow QSR={120}^0$