Aptitude - Height and Distance - Discussion
Discussion Forum : Height and Distance - General Questions (Q.No. 1)
1.
Two ships are sailing in the sea on the two sides of a lighthouse. The angle of elevation of the top of the lighthouse is observed from the ships are 30° and 45° respectively. If the lighthouse is 100 m high, the distance between the two ships is:
Answer: Option
Explanation:
Let AB be the lighthouse and C and D be the positions of the ships.
Then, AB = 100 m, 
ACB = 30° and ADB = 45°.
| AB | = tan 30° = | 1 |  AC = AB x 3 = 1003 m. |
| AC | 3 |
| AB | = tan 45° = 1 AD = AB = 100 m. |
| AD |
 CD = (AC + AD) |
= (1003 + 100) m |
| = 100(3 + 1) | |
| = (100 x 2.73) m | |
| = 273 m. |
Discussion:
104 comments Page 3 of 11.
Prasad said:
6 years ago
@All.
Know, how we get the 'tan'.
In the question is given we have to find the distance then that time we are not treating the angle of elevation so we have to take distance and hight then the formula becomes;
Tan=opp/adj.
Then AB/AC look at the figure it will be clear for you.
Know, how we get the 'tan'.
In the question is given we have to find the distance then that time we are not treating the angle of elevation so we have to take distance and hight then the formula becomes;
Tan=opp/adj.
Then AB/AC look at the figure it will be clear for you.
(1)
Jambay said:
5 years ago
How come √3 + 1?
(1)
Anjali tevari said:
5 years ago
How to find √3 value?
(1)
Raksha said:
1 year ago
Why are we using tan 30°? Please explain to me.
(1)
Pooja said:
10 months ago
Simple explanation:
The formula of tan; θ is,
tan θ = opposite side/adjacent side
So, we have angles 30° and 45° and the opposite side 100 m.
So, we can find an adjacent side.
The formula of tan; θ is,
tan θ = opposite side/adjacent side
So, we have angles 30° and 45° and the opposite side 100 m.
So, we can find an adjacent side.
(1)
Ravi said:
1 decade ago
Why we take AB/AC, AB/AD?
Sam said:
1 decade ago
Just remember root3=1.73 and root2=1.41
we take ab/ac because we want to find ac and we only know ab thats it
we take ab/ac because we want to find ac and we only know ab thats it
Srikanth said:
1 decade ago
Why you taken Tan and why you not taken cos ?
Jowy said:
1 decade ago
The tan30 is root(3) divide by 3. So how did you get root(3) ?
Mouli said:
1 decade ago
I am not understand jowy said.
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