# Aptitude - Height and Distance - Discussion

Discussion Forum : Height and Distance - General Questions (Q.No. 5)
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
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:
28 comments Page 1 of 3.

Deeps said:   9 months ago
Why can't we use sin30?

It is also perpendicular right?
(1)

Shivraj Singh said:   1 year ago
The value of √ 3 is 1.73.
(2)

Bala murali said:   2 years ago
Here, tan 30 is 1/√3.

Then how will 100/√3 become 1.73?
(2)

Sagar said:   3 years ago
1.73 how?
(1)

Vivek Sunny said:   3 years ago
Approach 1*1= 1,
1.5*1.5=2.25,
2*2=4,
so.

√ 3 is between 1.5 and 2 so 1.73 is correct.
(2)

Rutuja said:   3 years ago
how Root 3 is calculated as 1.73?

Vikas said:   3 years ago
Why tan only?

Because we find the height of the tower that we get tan30 because;

tan30 = perpendicular/base.

Mounika said:   3 years ago

Nissipravalika said:   4 years ago
Hi,

How to calculate √3 value?