Answer:
10701.97 feet.
Step-by-step explanation:
Refer the attached figure
The angle of elevation of a point, A, at the top of a cliff is 21° i.e. ∠ACB = 21°
The ship has sailed 2,500 feet directly toward the foot of the cliff i.e. CD = 2500 feet.
Then the angle of elevation becomes 47° i.e.∠ADB = 47°
Let BD be x
So, BC = BD+DC=x+2500
Let the height of the cliff be h feet.
In ΔABD
We will use trigonometric ratios
---a
In ΔABC
We will use trigonometric ratios
-----b
Equate a and b
Thus the height of the cliff is 10701.97 feet.
