SOLUTION: a 120 foot tall tower is to be erected on the side of the hill with a 6 degree angle from the horizontal. find the length of each of two support wires attached to the top of the to

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Question 1206921: a 120 foot tall tower is to be erected on the side of the hill with a 6 degree angle from the horizontal. find the length of each of two support wires attached to the top of the tower, if the first wire is anchored 135 feet uphill and the second wire is anchored 135 feet down the hill, from the base of the tower. if possible include a picture.
Answer by ikleyn(52790) About Me  (Show Source):
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a 120 foot tall tower is to be erected on the side of the hill with a 6 degree angle from the horizontal.
find the length of each of two support wires attached to the top of the tower,
if the first wire is anchored 135 feet uphill and the second wire is anchored 135 feet down the hill,
from the base of the tower. if possible include a picture.
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First wire is the side of an acute triangle, opposite to the angle 90° - 6° = 84°.
Two other sides of this triangle contain this angle and have the lengths 120 ft and 135 ft.


So, apply the cosine law

    the length of the first wire = sqrt%28120%5E2+%2B+135%5E2+-+2%2Acos%2884%5Eo%29%2A120%2A135%29 = sqrt%28120%5E2%2B135%5E2-2%2A0.1045285%2A120%2A135%29 = 170.1 ft (rounded).



Second wire is the side of an obtuse triangle, opposite to the angle 90° + 6° = 96°.
Two other sides of this triangle contain this angle and have the lengths 120 ft and 135 ft.


So, apply the cosine law

    the length of the second wire = sqrt%28120%5E2+%2B+135%5E2+-+2%2Acos%2896%5Eo%29%2A120%2A135%29 = sqrt%28120%5E2%2B135%5E2-2%2A%28-0.1045285%29%2A120%2A135%29 = 189.77 ft (rounded).

Solved.