Răspuns :
A = L₁×L₂×sin(L₁,L₂)
L₁ = AB = 8 cm
L₂ = BC = 7 cm
sin(L₁,L₂) = sin(∡ABC) = sin 30° = 1/2
A = 7×8×1/2 = 56/2 = 28
A = 28 cm²
L₁ = AB = 8 cm
L₂ = BC = 7 cm
sin(L₁,L₂) = sin(∡ABC) = sin 30° = 1/2
A = 7×8×1/2 = 56/2 = 28
A = 28 cm²