Question

In figure if $ QP\parallel SR$, the value of $ a$ is

• A. $40°$
• B. $30°$
• C. $90°$
• D. $80°$

Answer 1

The correct option is C

$90°$

Explanation for the correct option:

Compute the required value:

To determine the value of ‘$a$’, draw a line $XY$, to cut at ‘$a$’.

So, $XY\parallel SR$

$\angle XTS=\angle TSR=30°$ … [because interior alternate angles]

$\angle PQT=\angle QTX=60°$ … [because interior alternate angles]

Then, $a=\angle XTS+\angle QTX$

$=30°+60°$

$=90°$

Hence option $C$ is the correct answer.