[tex]\bold{a)} \ m(\ \textless \ A)_1=m(\ \textless \ A)_2=\frac{m(\ \textless \ A)}{2} \\ m(\ \textless \ A)=m(\ \textless \ BAC)=60^o \\ \Rightarrow m(\ \textless \ A)_1= \frac{60^o}{2} \\ \boxed{\bold{m(\ \textless \ A)_1=30^o}} \\ \bold{b)} \ m(\ \textless \ B)_1=m(\ \textless \ B)_2= \frac{m(\ \textless \ B)}{2} \\ m(\ \textless \ B)=m(\ \textless \ ABC)=80^o \\ \Rightarrow m(\ \textless \ B)_1=\frac{80^o}{2} \\ \boxed{\bold{m(\ \textless \ B)_1=40^o}} \\ \bold{c)} \ Orice \ triunghi \ are \ 360^o.[/tex]
