When shadow length equals height, find elevation: If the length of a pole’s shadow on level ground equals the pole’s height, what is the angle of elevation of the light source?

Difficulty: Easy

Correct Answer: 45°

Explanation:


Introduction / Context:
Same principle as similar items: tan θ = height/shadow. Equal height and shadow implies tan θ = 1 and θ = 45°.


Given Data / Assumptions:
Height = shadow; vertical pole; level ground.


Concept / Approach:
Use tan θ = opposite/adjacent.


Step-by-Step Solution:

tan θ = h / h = 1 → θ = 45°.


Verification / Alternative check:
A 45°-45°-90° triangle has equal legs, matching the condition.


Why Other Options Are Wrong:
30° and 60° correspond to √3 ratios, not equality; 75° would make a very short shadow.


Common Pitfalls:
Using sine/cosine instead of tangent; misinterpreting which angle is asked (elevation, not depression).


Final Answer:
45°

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