2Răspuns:
Explicație pas cu pas:D=3√3cm
In Δ dreptunghic ADB ∡BAD=30°⇒ BD=AB/2⇒ BD=3√3cm
teorema catetei
AB²=BD×BC 108=3√3BC 36=√3BC BC=36√3/3=12√3cm
DC=BC-BD=12√3-3√3=9√3cm
AC²=DC×BC=9√3×12√3=324 ⇒AC=18cm
P=18+12√3+6√3=18+18√3=18(1+√3) cm
a)A=AB×AC/2=18×6√3/2=54√3cm²
b)Aadb=AD×BD/2
Aadc=AD×DC/2
Aadb×/Aadc=BD/DC=3√3/9√3=1/3