Question

Va rog ajutor dau coroana

Answer 1

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