[tex]Fie~a,~b,~c~masurile[/tex]
[tex]a+b+c=180[/tex]
[tex]\frac{a}{n}=\frac{b}{n+1}=\frac{c}{n+2}=\frac{a+b+c}{n+n+1+n+2}=[/tex]
[tex]\frac{180}{3n+3}=[/tex]
[tex]\frac{180}{3(n+1)}=[/tex]
[tex]\frac{60}{n+1}[/tex]
[tex]a)~\frac{b}{n+1}=\frac{60}{n+1}\Rightarrow\ b=60[/tex]
[tex]Are~un~unghi~de~60~de~grade[/tex]
b) a+c=180°-60°=120°
i) c-a=20°
c=a+20°
a+a+20°=120°
2a=100°
a=50°
c=70°
ii) c=3a
a+3a=120°
4a=120°
a=30°
c=90°
