Answer:
BC ≈ 19.4 cm
Step-by-step explanation:
Using the cosine ratio in the right triangle
cos71° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{AB}{BC}[/tex] = [tex]\frac{6.3}{BC}[/tex] ( multiply both sides by BC )
BC × cos71° = 6.3 ( divide both sides by cos71° )
BC = [tex]\frac{6.3}{cos71}[/tex] ≈ 19.4 cm ( to 3 significant figures )
