a) tg B=AC/AB
2=6/AB⇒AB=3 cm
cu Pitagora BC=√(36+9)=3√5 cm
sin C=AB/BC=3/3√5=√5/5
b) sin B=AC/BC
12/13=AC/13⇒AC=12 cm
cu Pitagora
AB=√(169-144)=5 cm
tg C=AB/AC=5/12
c) cu Pitagora BC=√(9+27)=6 cm
sin B=AC/BC=3√3/6=√3/2 ⇒B=60*
d) din relatie AB=3BC/5
inlocuind avem
3BC/5 +BC=24
8 BC=24x5=120
BC=15 cm
AB=9 cm
AC=√(225-81)=12 cm