long casts a shadow 
long. At the same time, a tower casts a shadow 
long. Determine the height of the tower.Solution:
Given:
Length of stick = 
Length of the stick’s shadow = 
Length of the tower’s shadow = 
= 
To find:
The height of the tower = PQ.
In ΔABC ∼ ΔPQR
∠ABC = ∠PQR = 90o
∠ACB = ∠PRQ (Angular Elevation of Sun is same for a particular instant of time)
⇒ ΔABC ∼ ΔPQR (By AA similarity)
AB/BC = PQ/QR (Corresponding sides are proportional)
Therefore, 