CN Tower : The tallest free-standing tower in the world is the CN Towe...
Solution:
(i) Height of the CN Tower
Let AB be the CN Tower and C be the point of observation. Let BC = x and AB = h.
From the given information, we have:
Angle of elevation of the top of the tower from point C = 60°
Angle of elevation of the restaurant from point C = 45°
In right triangle ABC, we have:
tan 60° = AB/BC
√3 = h/x
h = x√3
In right triangle ABD, we have:
tan 45° = BD/AD
1 = BD/(h - 208)
h - 208 = BD
BD = h - 208
Substituting the value of h from equation (1), we get:
BD = x√3 - 208
In right triangle ACD, we have:
tan 60° = AD/AC
√3 = AD/(x + BD)
√3(x + BD) = AD
Substituting the value of BD from equation (2), we get:
AD = √3(x√3 - 208 + x)
AD = x√3 + 3x - 208√3
In right triangle ABD, we have:
sin 45° = BD/AD
1/√2 = (x√3 - 208)/[x√3 + 3x - 208√3]
Solving for x, we get:
x = 450
Substituting the value of x in equation (1), we get:
h = x√3 = 450√3 ≈ 778 m
Therefore, the height of the CN Tower is approximately 778 m.
(ii) Height of the restaurant above the ground
Let AB be the CN Tower and C be the point of observation. Let BC = x and AB = h.
From the given information, we have:
Angle of elevation of the top of the tower from point C = 60°
Angle of elevation of the restaurant from point C = 45°
In right triangle ABD, we have:
tan 45° = BD/AD
1 = BD/(h - 208)
h - 208 = BD
BD = h - 208
In right triangle ACD, we have:
tan 45° = CD/AC
1 = CD/(x + BD)
x + BD = CD
Substituting the value of BD from equation (1), we get:
CD = x + h - 208
In right triangle ABC, we have:
tan 60° = AB/BC
√3 = h/x
x = h/√3
Substituting the value of x in equation (3), we get:
CD = h - 208 + h/√3
CD = h(1 + 1/√3) - 208
CD = 778(1 + 1/√3) - 208 ≈ 335 m
Therefore, the restaurant is located approximately 335 m below the pinnacle of the tower.
CN Tower : The tallest free-standing tower in the world is the CN Towe...
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