Answer:
BC ≈ 18.7
Step-by-step explanation:
using the sine rule in Δ ABC
[tex]\frac{BC}{sinA}[/tex] = [tex]\frac{AC}{sinB}[/tex] ( substitute values )
[tex]\frac{BC}{sin67}[/tex] = [tex]\frac{20}{sin80}[/tex] ( cross- multiply )
BC × sin80° = 20 × sin67° ( divide both sides by sin80° )
BC = [tex]\frac{20sin67}{sin80}[/tex] ≈ 18.7 ( to the nearest tenth )
