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 1 of 5.
Anomie said:
2 years ago
@All.
According to trigonometry. We take sin θ when we should find either the opposite side value or the hypotenuse side value and we know either the hypotenuse side value or the opposite side value respectively.
Sin θ = opposite side value / Hypotenuse side value.
Same way We take cos θ when we should find either the hypotenuse side value or base side value and we know either the base side value or hypotenuse side value respectively.
Cos θ = base side value/Hypotenuse side value.
To take tan θ when we should find either the opposite side value or the base side value and we know either the base side value or the opposite side value respectively.
Tan θ = Opposite side value/base side value.
According to trigonometry. We take sin θ when we should find either the opposite side value or the hypotenuse side value and we know either the hypotenuse side value or the opposite side value respectively.
Sin θ = opposite side value / Hypotenuse side value.
Same way We take cos θ when we should find either the hypotenuse side value or base side value and we know either the base side value or hypotenuse side value respectively.
Cos θ = base side value/Hypotenuse side value.
To take tan θ when we should find either the opposite side value or the base side value and we know either the base side value or the opposite side value respectively.
Tan θ = Opposite side value/base side value.
(6)
Anil kumar behera said:
5 years ago
We all know that tan 60=AB/AC.
then, √(3)=AB/4.6,
then,4.6*√(3)=AB,
AB = 1.732 * 4.6.
AB = 7.967.
AB = 8.
then, √(3)=AB/4.6,
then,4.6*√(3)=AB,
AB = 1.732 * 4.6.
AB = 7.967.
AB = 8.
(5)
Lorddidah said:
4 years ago
Simply remember the code SOHCAHTOA.
SOH - Sine = Opposite/Hypotenuse.
CAH - Cos = Adjacent/Hypotenuse.
TOA - Tan = Opposite/Adjacent.
SOH - Sine = Opposite/Hypotenuse.
CAH - Cos = Adjacent/Hypotenuse.
TOA - Tan = Opposite/Adjacent.
(4)
Yeshi Samdup said:
4 years ago
Cos = adj/hyp
Cos60= 4.6m/hyp
0.5= 4.6m/hyp
Hyp= 4.6m/.
Therefore Hyp or length of ladder is 9.2m.
Cos60= 4.6m/hyp
0.5= 4.6m/hyp
Hyp= 4.6m/.
Therefore Hyp or length of ladder is 9.2m.
(4)
Fardeen khan said:
3 years ago
@All.
Here, actually, we want to find the (hypotenus) length of the ladder therefore we use "cos" = B/H (length's ledger).
Here, actually, we want to find the (hypotenus) length of the ladder therefore we use "cos" = B/H (length's ledger).
(2)
Ujjawal said:
3 years ago
Here, why we have used COS?
Because we have to find the length of the ladder and the length of ladder is the hypotenuse, perpendicular is wall nd base is foot from the ladder so as we know cos equals base upon hypotenuse. So, to get results we will use this as the data given to us fits for cos.
Because we have to find the length of the ladder and the length of ladder is the hypotenuse, perpendicular is wall nd base is foot from the ladder so as we know cos equals base upon hypotenuse. So, to get results we will use this as the data given to us fits for cos.
(2)
GAGAN said:
4 years ago
@Anil Kumar.
But they have asked BC not AB. Why are you finding AB?
But they have asked BC not AB. Why are you finding AB?
(1)
JIT said:
8 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:
8 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)
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