Question

17. The area of the 4 walls of a room is 168 m². The breadth and height is 10
and 4 m respectively. Find the length of the room.
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Answer 1

$\huge\underline\blue{\sf Answer:}$

$\large\red{\boxed{\sf Lenght\:of\:room(l)=11m }}$

$\huge\underline\blue{\sf Solution:}$

$\large\underline\pink{\sf Given: }$

• Area of room (A) = 168$\sf{{m}^{2}}$

• Breadth (b) = 10m

• Height (h) = 4m

$\large\underline\pink{\sf To\:Find: }$

• Lenght of the room (l) = ?

━━━━━━━━━━━━━━━━━━━━━━━━━

We know that ,

$\large{♡}$$\large{\boxed{\sf A=2(l+b)h }}$

On putting value :

$\large\implies{\sf 168=2(l+10)4}$

$\large\implies{\sf {\frac{168}{2×4}}=l+10}$

$\large\implies{\sf l+10=21}$

$\large\implies{\sf l=21-10 }$

$\large\implies{\sf l=11m }$

$\huge\red{♡}$$\large\red{\boxed{\sf Lenght\:of\:room(l)=11m }}$

Answer 2

Answer:

the perimeter of the floor is 168/4=42m

The Breath of the room is =4m

therefore the length of the room is={42-(4×2)}/2m

={42-8}/2m

=34/2m

=17m