Aptitude - Height and Distance - Discussion

@All.

Here, it is mentioned that the ladder is leaning on the wall, AB is the wall and BC is the ladder that's the reason we taken Tan.

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.

In this question, cos indicate is an adjacent side/hypotenuse side.

In the question, it's given that the foot of the ladder is 4.6m away from the wall. And we could take the given parameter to be either BC or AC. If it is the length of the ladder, then we should use sin and otherwise tan.

Why it will not be 7.8?

Also, we can take tan60,

AB/AC = tan60, =>AB=AC * tan60 =>AB= 4.6*tan60.

@All.

Take, Sin or Cos or Tan;

Sin = opposite/hypothesis
Cos = adjacent/hypothesis
Tan = opposite/adjacent.

Given are as following;

The angle is 60 degree.

The foot of leader is 4.6 m away from the wall (CA) this means 4.6m is adjacent,
A leader is leaning on the wall (CB) this will be hypothesis while determining (adjacent opposite or hypothesis but in real sense, it's the length of the leader!
Now, we can make out that it's Cos and not tan or sin because adjacent CA is given (4.6m) while hypothesis CB is x or unknown.

So,
Cos60 = CA/CB.
CB(x) = 4.6/cos60.
x = 9.2.

Thank You.

@Cynthia.

No wonder girls are dumb.

We want "BC" (the length of the ladder) not "AC" (height of the wall).

Can we do it taking tan?

Shyam and Asish,

Absolutely we can take tan.
but if we take tan we will get AB.
Then we have to take sin to find length of the ladder, i.e BC.

It 'll take more time..so only we take cos in this problem.

Nikita great Ans thanks