Răspuns:
a) Triunghi isoscel => AB=AC
P= AB+AC+BC
AB+AB+ [tex]\frac{6AB}{5}[/tex]=96 2*AB+[tex]\frac{6AB}{5}[/tex]=96 aducem la acelasi numitor
10 AB+6AB= 96*5 16 AB= 96*5
AB= [tex]\frac{96*5}{16}[/tex]= 6*5=30 cm AB=AC=30 cm
BC= 96-2*30= 96-60=36 cm BC=36 cm
b) m(ABC) + m(BAC) + m(ACB)=180 °
triunghi isoscel=> m(A) =m(B) sau m(A)=m(C)
2*m(A)+m(C)=180°
BD= AC/2 =30/2=15 cm
sin (BAC)=[tex]\frac{BD}{AB}[/tex]= [tex]\frac{15}{30} =\frac{1}{2}[/tex] => m(BAC)=30 °
