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.
JIT said:
9 years ago
If we take,
tan30=AC/BC,
BC=7.8.
Why can't we solve in this way?
tan30=AC/BC,
BC=7.8.
Why can't we solve in this way?
(1)
Prasanna kumar said:
9 years ago
Why was the down angle is 60 degrees, angle of elevation means top angle should be top angle should be zero?
(1)
Praveen kumar said:
9 years ago
Great answer Thanks @Rahul Rami.
(1)
Rajan said:
9 years ago
Why can't we use sec instead of cos?
(1)
Jayanth said:
6 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:
5 years ago
why we take cos here? Explain please.
(1)
Eben Thomas said:
4 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)
Cynthia said:
1 decade ago
Why can't we take in this way:
Tan 60 = AB/4.6.
1.73 = AB/4.6.
AB = 7.958.
Tan 60 = AB/4.6.
1.73 = AB/4.6.
AB = 7.958.
(1)
Shiyamala maths said:
1 decade ago
sin=Opposite side/hypotenuse
cos=adjacent side/hypotenuse
tan=opposite/adjacent
AC=4.6
We know adjacent side that is only we are using cos
cos{60)=A.s/Hypo=1/2
=AC/AB = 1/2 {cross multiplication)
=2(AC)=AB
2(4.6)=AB
9.2=AB
cos=adjacent side/hypotenuse
tan=opposite/adjacent
AC=4.6
We know adjacent side that is only we are using cos
cos{60)=A.s/Hypo=1/2
=AC/AB = 1/2 {cross multiplication)
=2(AC)=AB
2(4.6)=AB
9.2=AB
(1)
Prasad Chachadi said:
8 years ago
Here, the elevation with respect to the wall but in the solution, it is taken with respect to the land!
Please correct me, if I am wrong.
Please correct me, if I am wrong.
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