Question

Question 7
A flag pole 18 m high casts a shadow 9.6 m long. Find the distance of the top of the pole from the far end of the shadow.

Answer 1

Let BC = 18 m be the flag pole and the shadow be AB = 9.6 m. The distance of the top of the pole, C from the far end i.e. A of the shadow is AC.

In right angled $\Delta ABC$,
$A{C}^2=A{B}^2+B{C}^2$ [by Pythagoras theorem]
$\Rightarrow A{C}^2=(9.6{)}^2+(18{)}^2$
$A{C}^2=92.16+324$
$\Rightarrow A{C}^2=461.16$
$\therefore AC=\sqrt{416.16}=20.4m$
Hence, the required distance is 20.4 m because distance can not be in negative.