A ladder rests against a wall at an angle α to the horizontal. Its foot is pulled away from the wall through a distance a, so that it slides a distance b down the wall making an angle β with the horizontal. Show that ![]()
In the fig let the length of ladder is h (m)
In ∆AEB
Sin α = ![]()
Sin α = ![]()
AE = h Sin α
Cos α = ![]()
Cos α = ![]()
BE = h Cos α
In ∆DEC
Sin β = ![]()

Sin β = ![]()
DE = h Sin β
Cos β = ![]()
Cos β = ![]()
CE = h Cos β
Now
= ![]()
= ![]()
= ![]()
=
Proved