Răspuns :
[tex]\it d=BC\ (diametru) \Rightarrow m(\widehat{A})=90^o\\ \\ m(\widehat C)=30^o\ \ (complementul\ lui\ 60^o)\\ \\ T.\angle\ 30^o \Rightarrow d=BC=2AB=2\cdot3=6\ cm\\ \\ L_{cerc}=d\cdot \pi=6\pi\ cm[/tex]
[tex]\it d=BC\ (diametru) \Rightarrow m(\widehat{A})=90^o\\ \\ m(\widehat C)=30^o\ \ (complementul\ lui\ 60^o)\\ \\ T.\angle\ 30^o \Rightarrow d=BC=2AB=2\cdot3=6\ cm\\ \\ L_{cerc}=d\cdot \pi=6\pi\ cm[/tex]