Calculating the Area of Four Walls

The question asks for the total area of the four walls of a room given its dimensions: length (l), breadth (b), and height (h).

Area Formula for Four Walls

The area of the four walls of a rectangular room is calculated using the perimeter of the floor multiplied by the height of the room. The formula is:

Area = $2 \times (\text{length} + \text{breadth}) \times \text{height}$

In mathematical terms:

Area = $2(l + b)h$

Applying Given Dimensions

Given values are:

• Length ($l$) = 15 m
• Breadth ($b$) = 20 m
• Height ($h$) = 30 m

Step-by-Step Calculation

1. Sum the length and breadth: $l + b = 15 \text{ m} + 20 \text{ m} = 35 \text{ m}$
2. Calculate the perimeter of the floor: Perimeter = $2 \times (l + b) = 2 \times 35 \text{ m} = 70 \text{ m}$
3. Calculate the area of the four walls: Area = Perimeter $\times$ height Area = $70 \text{ m} \times 30 \text{ m}$ Area = $2100 \text{ m}^2$

Final Answer

The area of the four walls of the room is $2100 \text{ m}^2$. This corresponds to Option C.