Aptitude - Height and Distance - Discussion
Discussion Forum : Height and Distance - General Questions (Q.No. 3)
3.
The angle of elevation of a ladder leaning against a wall is 60° and the foot of the ladder is 4.6 m away from the wall. The length of the ladder is:
Answer: Option
Explanation:
Let AB be the wall and BC be the ladder.
Then, 
ACB = 60° and AC = 4.6 m.
| AC | = cos 60° = | 1 |
| BC | 2 |
 BC |
= 2 x AC |
| = (2 x 4.6) m | |
| = 9.2 m. |
Discussion:
45 comments Page 2 of 5.
Rajan said:
9 years ago
Why can't we use sec instead of cos?
(1)
Sahil said:
8 years ago
We can do it using tan also.
(1)
Viraj said:
8 years ago
How to find √3?
(1)
Jayanth said:
5 years ago
Here, they asked about the length of the ladder, not about the hypotenuse.
So the correct answer is 7.8m.
So the correct answer is 7.8m.
(1)
Deepali said:
4 years ago
why we take cos here? Explain please.
(1)
Eben Thomas said:
3 years ago
sin=o/h , cos=a/h, tan=o/a,
Here,
o- Opposite side;
h-Hypotnuse;
a- Adjasent side.
Here,
o- Opposite side;
h-Hypotnuse;
a- Adjasent side.
(1)
Student said:
8 months ago
How to identify when we use tan, cot or sin function? Anyone please clarify.
(1)
Bhavy said:
7 years ago
@All.
Sin=perpendicular. Upon hypotenuse and cos, =base upon hypotenuse and tan=perpendicular upon base. And in this question, we need hypotenuse so cos is applied.
Sin=perpendicular. Upon hypotenuse and cos, =base upon hypotenuse and tan=perpendicular upon base. And in this question, we need hypotenuse so cos is applied.
Niezel said:
6 years ago
By using tan you'll end up getting AB which is B the height of the wall but the problem says to find for the length of the ladder then use the value of AB and AC using Pythagorean's theorem c= √(a^2+b^2).
Then BC= √(AB^2 + AC^2) then you"ll get the length of the ladder.
Then BC= √(AB^2 + AC^2) then you"ll get the length of the ladder.
Brinda said:
6 years ago
@Chiru.
Yes, you are right and when Tan is taken answer is 7.9.
Yes, you are right and when Tan is taken answer is 7.9.
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