Difficulty: Easy
Correct Answer: 3 : 1
Explanation:
Introduction / Context:
With observation at the midpoint between the bases, the horizontal distances to the two towers are equal. Thus heights are proportional to tan of their elevation angles at the same base distance.
Given Data / Assumptions:
Concept / Approach:
h ∝ tan θ when horizontal distance is constant. Therefore, ratio of heights = tan 60° : tan 30° = √3 : (1/√3) = 3 : 1.
Step-by-Step Solution:
Verification / Alternative check:
If both angles were 45°, the ratio would be 1 : 1. Here, 60° to one tower ensures it is three times the other for the same d.
Why Other Options Are Wrong:
2 : 1 or √3 : 1 ignore tan 30° = 1/√3; 3 : 2 understates the difference.
Common Pitfalls:
Using sin/cos instead of tan; assuming unequal distances when “midpoint” guarantees equality.
Final Answer:
3 : 1
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