In triunghiul dreptunghic ADB, tg∠B=AD/BD =√3 => ungh B=60 grade . In triunghiul dreptunghic ABC, ungh A=90, ungh B=60 => u gh C= 30. Potrivit th ungh 30 grade => AB=BC/2 . Da notam AB cu x=> BC=2x. In tr ABC aplicM th pitagora => BC²=AC²+AB²=> 4x²=36+x² => 3x²=36 => x²=12 => x=√12 =>x=2√3 deci AB=√3. Aria tr ABC=c1*c2/2=6*√3/2=3√3
