The angle of elevation and depression of the top and bottom of another building, measured from the top of a 24 m tall building, is 30° and 60°, respectively. Determine the second building's height.
A.
24 m
B.
32√3m
C.
24√3
D.
32 m
Correct Answer: 32 m
Explanation
The height of the second building H = h + 24
tan θ = opp/adj
tan 30° = h/x
⟹3√3 = h/x
⟹x = √3 = 3h
⟹x = 3h/√3 ....(i)
tan 60° = 24/x
⟹√3 = 24x
⟹x√3 = 24
⟹x = 24/√3 ....(ii)
Equate equation (i) and (ii)
⟹3h/√3 = 24/√3
⟹ 3h = 24
⟹h = 24/3 = 8m
∴The height of the second building = 8 + 24 = 32m
The height of the second building H = h + 24
tan θ = opp/adj
tan 30° = h/x
⟹3√3 = h/x
⟹x = √3 = 3h
⟹x = 3h/√3 ....(i)
tan 60° = 24/x
⟹√3 = 24x
⟹x√3 = 24
⟹x = 24/√3 ....(ii)
Equate equation (i) and (ii)
⟹3h/√3 = 24/√3
⟹ 3h = 24
⟹h = 24/3 = 8m
∴The height of the second building = 8 + 24 = 32m