Aria unui triunghi mai poate fi calculata si cu formula (predata la scoala):
S=1/2×AB×AC×sin(BAC)=1/2×8×12×rad(3)/2= 96×rad(3)
Deci S=96×rad(3) cm^2
BD=AB×sin(60)=8×rad(3)/2=4×rad(3) cm
AD=AB×cos(60)=8/2=4 cm
DC=AC-AD=12-4=8 cm
Triunghiul BDC dreptunghic
BC^2=BD^2+DC^2=48+64=112
BC=rad(112)=rad(16×7)=4×rad(7) cm.
Raspuns:
S=96×rad(3) cm^2
BC=4×rad(7) cm
