Answer:
Last option 527.7 ft
Explanation:
From the diagram attached we can see the angle of depression is 80.2 which is equal to ∠ACB (alternate angles)
Height of the deck AB = 520 ft. and we have to calculate the distance H between the tourist and her friend.
Sin ∠ACB =

Now we apply sin rule sin 80.2 =



So the tourist and her friend are 527.7 ft apart.