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Aptitude - Height and Distance - Discussion

Discussion Forum : Height and Distance - General Questions (Q.No. 5)
Height and Distance
5.
From a point P on a level ground, the angle of elevation of the top tower is 30°. If the tower is 100 m high, the distance of point P from the foot of the tower is:
149 m
156 m
173 m
200 m
Answer: Option
Explanation:

Let AB be the tower.

Then, APB = 30° and AB = 100 m.

AB = tan 30° = 1
AP 3

AP = (AB x 3) m
= 1003 m
= (100 x 1.73) m
= 173 m.

Discussion:
29 comments Page 2 of 3.
Mallikarjuna said:   8 years ago
Hi,

Why here we are not using sin, we will get an answer of 200 if use sin but you are using the formula of tan. Can you give us an explanation?
Sankar said:   8 years ago
I think there is a mistake in the answer. Here really we have to use sin as what we need to find out is adjacent side.
Krishi said:   8 years ago
@Sankar,

In sin there is perpendicular and hypotenuse.

But we have to find base we cannot use cos also because hypotenuse is not given. Remaining tan which is used.
Vaibhav shelar said:   8 years ago
No, according to 30-60-90 theorem rule answer must be 100√(3).
Yashoda suji said:   7 years ago
Can't we use sin here?
Sanjau said:   7 years ago
√ 3 value is 1.73 and 100 x 1.73=173.
Vansh giroh said:   7 years ago
Here AP needs to find so using the AB value Tan 30 is taken and root 3 is 1.73. So the answer will be 173m.
Priya said:   6 years ago
Thank you so much @Sarthak.

You explained it neat and clear.
Gitanshu said:   6 years ago
How to divide 34.64/1.732 without calc. Is there any simple trick?
(2)
Nissipravalika said:   5 years ago
Hi,

How to calculate √3 value?

Anyone can explain please?
(1)
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