Respuesta :
Answer:
The boat is 192 feet from the cliff.
Explanation:
Hi there!
Please see the attached figure for a graphical description of the problem.
Notice that the line of sight, the distance to the cliff and the height to the top of the lighthouse form a right triangle. Hence, we can apply trigonometric rules to find the distance from the boat to the cliff:
cos 20° = adjacent side / hypotenuse
sin 20° = opposite side / hypotenuse
The length of the opposite side is the height of the cliff plus the height of the lighthouse:
opposite side = 45 feet + 25 feet = 70 feet.
Using the equation of sin 20°, we can obtain the hypotneuse:
sin 20° = opposite side / hypotenuse
hypotenuse · sin 20° = opposite side
hypotenuse = opposite side / sin 20°
hypotenuse = 70 feet / sin 20°
hypotenuse = 205 feet
Now, using the equation of cos 20°, we can calculate the distance to the cliff (the length of the adjacent side):
cos 20° = adjacent side / hypotenuse
hypotenuse · cos 20° = adjacent side
205 feet · cos 20° = adjacent side
adjacent side = 192 feet (without rounding intermediate results)
The boat is 192 feet from the cliff.
Answer:
192 ft.
Explanation:
Tan (20) = Opp/Adj
Tan (20) = (45+25)/x
Tan (20) = 70/x
then x=70/Tan (20)
x= 192.3234 ft, and then rounded to the nearest foot...
x= 192 ft