The length, width, and height of a room are 7 m, 8 m, and 9 m respectively. What is the total area of the walls?
Answer & explanation
Correct answer: option 1
A shape of room is cuboidal, thus the formulae of total surface area of walls is:
The area of the 4 walls is: l × h + l × h + b × h + b × h
The area of the 4 walls is: 2lh + 2bh
The area of the 4 walls is: 2h (l + b)
So, according to the question:
2h (l + b) = 2 × 9 (7 + 8)
Total area of the walls = 18 (15) = 270 cm2