1)MN²=LM²+LN²-2*LM*LN*cosL ⇒ MN²=.36+81-54 MN=√63=3√7 cm 2) m(<B)=180°-(75°+60°)=45° ΔBNA-dreptunghic isoscel ,BN=AN AB²=BN²+AN² ⇒32=2AN² ⇒AN²=16 ⇒AN=4 cm din ΔANC- dreptunghic sin C=AN/AC ⇒sin60°=4/AC ⇒AC= 4/sin 60° ⇒AC=8/(√3)=(8√3)/3 cm NC=1/2*AC(cateta opusa unghiului de 30°) NC=(4√3)/3 cm BC=BN+NC=4+(4√3)/3=(12+4√3)/3 cm
