Answer:
5.25 miles
Step-by-step explanation:
We are required to determine the distance between Lighthouse A and Lighthouse B in the diagram.
Using Law of Cosines
[tex]c^2=a^2+b^2-2abCosC\\c^2=7^2+4^2-2(7)(4)Cos48^\circ\\c^2=27.5287\\c=\sqrt{27.5287} \\c=5.25\: miles[/tex]
The distance between lighthouses is 5.25 miles.
