Question

In the given figure, AB is a straight line. If $\angle AOC={50}^{\circ }$ and $\angle DOB={60}^{\circ }$, then x = ______ .

• A. ${60}^{\circ }$
• B. ${70}^{\circ }$
• C. ${80}^{\circ }$
• D. ${90}^{\circ }$

Answer 1

The correct option is B ${70}^{\circ }$

${50}^{\circ }+{60}^{\circ }+x^{\circ }={180}^{\circ }$ ...(angles on a straight line)

${110}^{\circ }+x^{\circ }={180}^{\circ }$

$\therefore x={70}^{\circ }$