Aptitude - Height and Distance - Discussion

Also according to the position of angle. We decide which one is opposite side and which one is adjacent. So remember the formula for each Sin, Cos, and Tan and solve the problem easily.

Its very simple @Sreeja.

If we have perpendicular (AB) and say to find hypotenuse (BC) then we use sin Angle.

If we have perpendicular (AB) and say to find Base (AC) then we use tan Angle.

If we have Base (AC) and say to find Hypotenuse (BC) then we use Cos angle.

Note : AB, AC, BC are taken from the solution of this question,

In above example, we have a base (AC) and say to the fine length of ladder means find hypotenuse (BC).

So we can use Cos Angle in this situation.

How can we remember here we should use "Tan" and there we should use "Cos"?

They are asking 4.6 m away from the wall. But here its get attach with the wall. How come?

@Cynthia.

No wonder girls are dumb.

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

tan60 = x/4.6.

x = tan60*4.6.
x = 1.732*4.6.

Therefore, x = 7.8.

Can't we do this with the 30, 60, 90 triangle method?

Why we are using cos here?

Short cut of sin, cos, tan are.

sin = old/harry (opposite/hypotenuse).
cos = and/his (adjacent/hypotenuse).
tan = old/aunty (opposite/adjacent).

(note:check first letter).

Why can't we take in this way:

Tan 60 = AB/4.6.

1.73 = AB/4.6.
AB = 7.958.