Flagstaff shadow — find the Sun’s angle with the ground: A vertical flagstaff of height 6 m casts a shadow of length 2√3 m on level ground. What is the angle of elevation of the Sun (in degrees)?

Difficulty: Easy

Correct Answer: 60°

Explanation:


Introduction / Context:
Shadow questions model a right triangle with height as the opposite side and shadow as the adjacent side; thus tan(θ) = height / shadow. Using exact radical values allows a clean angle result.



Given Data / Assumptions:

  • Height = 6 m
  • Shadow = 2√3 m
  • Ground is horizontal; flagstaff is vertical.


Concept / Approach:
Compute tan θ and recognize a standard angle whose tangent equals √3.



Step-by-Step Solution:
tan θ = 6 / (2√3) = 3 / √3 = √3Therefore, θ = 60° (since tan 60° = √3)



Verification / Alternative check:
Using numeric √3 ≈ 1.732, tan θ ≈ 1.732 ⇒ θ ≈ 60°; consistent with standard trigonometric values.



Why Other Options Are Wrong:
At 30°, tan = 1/√3; at 45°, tan = 1; at 75°, tan is much larger than √3. “None” is unnecessary since an exact match exists.



Common Pitfalls:
Inverting the ratio (shadow/height) and using cot instead of tan; mixing degrees and radians.



Final Answer:
60°

More Questions from Height and Distance

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion