Răspuns:
Explicație pas cu pas:
Ducem AD⊥BC
in Δ ABD dreptunghic
sin B=AD/AB ∡B=30° ⇒1/2=AD/AB AD=3 cm
BD=AB cos∡B=6√3/2=3√3 cm
in ΔADC dreptunghic
AD=DC ∡C=45° DC=3 cm
AC=AD√2 AC=3√2 cm
BC=BD+DC=3√3+3 cm
P=AB+AC+BC=6+3√2+3√3+3=9+3√2+3√3 cm
A=ADxBC/2=3×3(√3+1)/2=4,5(√3+1) cm²