Final answer:
To find the area of the four walls of the room, calculate the perimeter by adding all the sides of the room. Then, multiply the perimeter by the height of the room to get the area of the four walls.
Step-by-step explanation:
To find the area of the four walls of the room, we need to first calculate the perimeter of the room. The perimeter is the sum of all the sides. In this case, the two sides with length 8cm and 7cm make up the length of the room, and the two sides with length 12cm and 7cm make up the breadth of the room.
Perimeter = 2(length + breadth)
Now, we can calculate the area of the four walls by multiplying the perimeter by the height of the room:
Area of four walls = Perimeter * Height
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