Question

In the given figure, O is the centre of a circle and $\angle OAB={50}^{\circ }$. Find $\angle BOD$.

• A. ${50}^{\circ }$
• B. ${100}^{\circ }$
• C. ${80}^{\circ }$
• D. ${130}^{\circ }$

Answer 1

The correct option is B ${100}^{\circ }$

$OA=OB$ (radii of the same circle)
$\Rightarrow \angle OBA=\angle OAB={50}^{\circ }$
In $\Delta OAB,$ we have:
$\angle BOD=\angle OAB+\angle OBA$
$\angle BOD={50}^{\circ }+{50}^{\circ }$
$\angle BOD={100}^{\circ }$