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.

Home » 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.

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.

Solution:

NCERT Exemplar Solutions Class 10 Maths Chapter 6 Ex. 6.4-16

Let MN the flag pole = 18 m and its shadow LM = 9.6 m.

The distance of the top of the pole be LN, N from the far end, L of the shadow.

By Pythagoras theorem in right angled ∆LMN,

$L{{N}^{2}}~=\text{ }L{{M}^{2}}~+\text{ }M{{N}^{2}}$

$\Rightarrow ~L{{N}^{2}}~=\text{ }{{\left( 9.6 \right)}^{2}}~+\text{ }{{\left( 18 \right)}^{2}}$

$\Rightarrow ~L{{N}^{2}}~=\text{ }9.216\text{ }+\text{ }324$

$\Rightarrow ~L{{N}^{2}}~=\text{ }416.16$

$\therefore ~LN\text{ }=\surd 416.16\text{ }=\text{ }20.4\text{ }m$

As a result, 20.4 m is the required distance.

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