Question

The area of four walls of a room is $91{m^2}$. If the room is 13 m long and 4.5 m broad. Find its height.

Answer 1

Hint: To solve this question, we have to remember that the shape of a room is like a cuboid and the formula of area of four walls of a cuboid is given as: $2\left( {l + b} \right)h$. The area of four walls is also known as the lateral surface area.

Complete step-by-step answer:
Given that,
Area of four walls of a room is $91{m^2}$.
Length of the room = 13 m.
Breadth of the room = 4.5 m
We have to find the height of the room.
We know that,
The shape of a room is like a cuboid.
We also know that,
The area of four walls of a cuboid = $2\left( {l + b} \right)h$.
Putting all the given values, we will get
\[
   \Rightarrow 91 = 2\left( {13 + 4.5} \right)h \\
   \Rightarrow 91 = 2\left( {17.5} \right)h \\
   \Rightarrow 91 = 35h \\
   \Rightarrow \dfrac{{91}}{{35}} = h \\
   \Rightarrow h = 2.6m \\
\]
Hence, we can say that the height of the room is 2.6 m.

Note: Whenever we ask this type of question, we have to remember the basic formulae of different shapes such as lateral surface area, total surface area, volume etc. first, we have to find out all the given details. After that, we will identify the appropriate formula required in that question. Then we will put all the known values in that formula and by solving that, we will get the other unknown values from that formula.