Answer:
A
Step-by-step explanation:
Using the Sine rule in Δ ABC
∠ B = 180° - (30 + 50)° = 180° - 80° = 100° ( sum of angles in triangle ) , then
[tex]\frac{13}{sin100}[/tex] = [tex]\frac{BC}{sin30}[/tex] ( cross- multiply )
BC × sin100° = 13 × sin30° ( divide both sides by sin100° )
BC = [tex]\frac{13sin30}{sin100}[/tex] ≈ 6.6 ( to the nearest tenth )
