Question

In the above figure, $O$ is the centre of the circle and $\angle BAC=n^{\circ }$, $\angle OCB=m^{\circ }$ then

• A. $m^{\circ }+n^{\circ }={90}^{\circ }$
• B. $m^{\circ }+n^{\circ }={180}^{\circ }$
• C. $m^{\circ }+n^{\circ }={120}^{\circ }$
• D. $m^{\circ }+n^{\circ }={150}^{\circ }$

Answer 1

The correct option is A $m^{\circ }+n^{\circ }={90}^{\circ }$

In $△OBC$
$m+m+2n={180}^o$ [Since the sum of the angles of a triangle $={180}^o$]
$m+n={90}^{\circ }$