Question

Find the area of four walls of a room (Assume that there no doors and windows) if its lengths \[12m.,\] breadth \[10m.\] and height \[7.5m.\]

Answer 1

Hint: In order to find the area of four walls of a room after assuming that there are no doors and windows, we need to find the lateral surface area of the cuboid as the room is considered a cuboid.

Complete step-by-step solution:
We have been given, length of a room \[ = {\text{ }}12m\]
We are also been given the breadth of the room \[ = {\text{ }}10m\]
And also given, height of the room \[ = {\text{ }}7.5m\]
Using the above information, we will construct a diagram of a room, assuming there are no doors and windows.

Now, let us look at the diagram, we can see the room is in a form of cuboid. So, for the area of four walls, we can use the lateral surface area of the cuboid.
We know that, lateral surface area of cuboid \[ = {\text{ }}2\left( {L + B} \right)H\]
So, Area of four walls \[ = {\text{ }}2\left( {L + B} \right)H\]
\[\begin{array}{*{20}{l}}
  { = {\text{ }}2\left( {12 + 10} \right)7.5} \\
  { = {\text{ }}2\left( {22} \right)7.5} \\
  { = {\text{ }}330{m^2}}
\end{array}\]

Thus, area of four walls of the room is \[330{m^2}.\]

Note:Students need to take care that to evaluate the area of four walls of a room, we need to consider it as a cuboid and then we need to find the lateral surface of it.