Answer:
AB ≈ 6.53
Step-by-step explanation:
using the cosine ratio in the right triangle
cos40° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{AC}{AB}[/tex] = [tex]\frac{5}{AB}[/tex] ( multiply both sides by AB )
AB × cos40° = 5 ( divide both sides by cos40° )
AB = [tex]\frac{5}{cos40}[/tex] ≈ 6.53 ( to the nearest hundredth )
