Question

In the adjoining figure ABCD is parallelogram then the measure of x is

• A. ${45}^{\circ }$
• B. ${60}^{\circ }$
• C. ${90}^{\circ }$
• D. ${135}^{\circ }$

Answer 1

The correct option is C ${90}^{\circ }$

$\angle A+\angle B={180}^o$

$\therefore 60+60+y={180}^o$$\Rightarrow y={60}^o$

Now in $\Delta AOB$
$\angle O=180-(30+60)$$={90}^o$

$\therefore \angle x={90}^o$ [vertically opposite].