Question

PQR is a straight line.

What is the value of x?

• A. ${20}^{\circ }$
• B. ${25}^{\circ }$
• C. ${15}^{\circ }$
• D. ${30}^{\circ }$

Answer 1

The correct option is A ${20}^{\circ }$

Given PQR is a straight line.
$\therefore \angle PQR={180}^{\circ }$
$\Rightarrow \angle PQS+\angle SQT+\angle TQR={180}^{\circ }$
$\Rightarrow 2x+{120}^{\circ }+x={180}^{\circ }$
$\Rightarrow 3x={60}^{\circ }$
$\Rightarrow x={20}^{\circ }$