Question:
A 15 high tower casts a shadow 24 Long at a certain time and at the same time, a telephone pole casts a shadow 16 long. Find the height of the
telephone pole.
Solution:
Let BC = 15 m be the tower and its shadow AB is 24 m. At that time ∠CAB = 8, Again, let EF = h be a telephone pole and its shadow DE = 16 m. At
the same time ∠EDF = 8 Here, ΔASC and ΔDEF both are right angled triangles.
In $\triangle A B C$ and $\triangle D E F$, $\angle C A B=\angle E D F=\theta$
$\angle B=\angle E$ [each 90°]
$\therefore$ $\triangle A B C \sim \triangle D E F$ [by AAA similarity criterion]
Then, $\frac{A B}{D E}=\frac{B C}{E F}$
$\Rightarrow$ $\frac{24}{16}=\frac{15}{h}$
$\therefore$ $h=\frac{15 \times 16}{24}=10$
Hence, the height of the telephone pole is 10 m.