iran-konkur 2015 Q125

iran-konkur · Other · konkur-riazi_1394 Not Maths
125- In a circle with center $O$, we extend the radius $OA$ to point $B$ such that $B$ is tangent to the circle. The perpendicular $BD$ is dropped to the circle. If $\widehat{ADB} = 34°$, the angle $OAD$ is how many degrees?
  • [(1)] $68$
  • [(2)] $73$
  • [(3)] $107$
  • [(4)] $146$
\textbf{125-} In a circle with center $O$, we extend the radius $OA$ to point $B$ such that $B$ is tangent to the circle. The perpendicular $BD$ is dropped to the circle. If $\widehat{ADB} = 34°$, the angle $OAD$ is how many degrees?

\begin{itemize}
\item[(1)] $68$
\item[(2)] $73$
\item[(3)] $107$
\item[(4)] $146$
\end{itemize}