Răspuns :
[tex]\it Not\breve am\ \widehat{BOC} =x,\ \ \widehat{AOC}=y\\ \\ \widehat{BOD}=\widehat{AOC}=y\\ \\ x+y=180^o\ \ \ \ \ (*)\\ \\ 2x=3y|_{+2y} \Rightarrow 2x+2y=5y \Rightarrow 2(x+y)=5y\ \stackrel{(*)}{\Longrightarrow}\ 360^o=5y|_{:5} \Rightarrow y=72^o[/tex]