Aptitude - Height and Distance - Discussion

Discussion Forum : Height and Distance - General Questions (Q.No. 6)
6.
The angle of elevation of the sun, when the length of the shadow of a tree 3 times the height of the tree, is:
30°
45°
60°
90°
Answer: Option
Explanation:

Let AB be the tree and AC be its shadow.

Let ACB = .

Then, AC = 3         cot = 3
AB

= 30°.

Discussion:
62 comments Page 2 of 7.

Vaibhav said:   5 years ago
Thank you all for explaining.
(1)

Lory said:   5 years ago
I can't understand the question yet.
(1)

Ravi said:   5 years ago
Here we solve the problem by using the angle of depression. Let β the angle of depression made by the sun on the tree.

Then angle β is equal to the angle of BCA.

Given the length of shadow is √3 times the height of tree i.e., AC=√3AB.

tanβ = AB/AC = AB/√3AB = 1/√3

tanβ = tan30° =>β = 30°.
(3)

Aditya said:   6 years ago
I think answer would be 60° because here angle of elevation of the Sun is asked.

As angle of elevation of the sun increases the length of shadow Decreases and vice versa.

Vijay Kumar said:   6 years ago
@All.

tanθ=AB/AC = x/√3x.
tanθ=1/√3.

In the important formula table, they were given that the value of tan30 = 1/√3.
Hence here the value of θ becomes 30.

Nisha said:   6 years ago
Thanks @Balaji.

Aravind said:   6 years ago
AB/AC=1/√3.
TANθ=30θ.
(1)

Sai Aswin said:   6 years ago
SHORT CUT:

Shadow=√3(height of the tree).
(Shadow/height of tree)= √3,
So, cotθ = √3=30°.

Pranit Raj said:   6 years ago
Can also the answer be 60° If we consider tan.

Jeslin said:   7 years ago
Let tree AB=x.

Shadow AC= √3 times height of the tree.
so, AC= √3x.
Here, the opposite and adjacent sides are involved so, we are using tan.
Tan theta = opp/adj =AB/AC =x/√3x =1/√3.
Theta = tan inverseof( 1/√3).
Theta=30°.
(we know that tan 30° =1/√3).
Hope it helps.


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