Question

3. The area of four walls of a room is 90 m².If the room is
7 m long and 2 m wide, then
find the height of the room​

Answer 1

Step-by-step explanation:

Height of the room is 5 cm.

Step-by-step explanation:

Given:

Four walls of the room means lateral surface area.

We assume the room to be Cuboid as most rooms are in the

form of a Cuboid.

Lateral Surface area of the Room = 90 m^{2}m

2

Length of the Room = 7 meters

Breadth of the Room = 2 meters

Formula to find the Lateral Surface area of a Cuboid = 2h(l + b)

Substituting the values known to us in the Formula used to find the Lateral Surface Area of the Cuboid:

=> 2h(l + b)

=> 2h(7 + 2) = 90

=> 2h(9) = 90

=> 9h = 90 / 2 = 45

=> 9h = 45

=> h = 45 / 9 = 5

=> 5 cm

Therefore, Height of the room is 5 cm.

Answer 2

Answer:

$\boxed{\sf Height = 5m}$

Step-by-step explanation:

Area of four walls of a room is 90m²

Since , it is said that 90m² , is the area of four walls of the room the top and bottom of the room is excluded .

So the given area is the LSA of the room.

Also since the length and breadth are given the room must be in the shape of a cuboid.

Lateral Surface area (LSA) of cuboid = 2(l + b)h

Here,

Length(l) = 7m

Breadth (b) = 2m

Height(h) = ?

Substituting the know values in Formula of Lateral Surface area (LSA) of cuboid, we get

2(7+2)h = 90m²

2 × 9h = 90m²

9h = 45m²

$\sf h = \dfrac{45}{9}$

Therefore , Height of the room​(h) = 5m.