Question

The perimeter of the floor of a room is 18 m and its height is 3 m. What is the area of 4 walls of the room?

(a) 21 m²
(b) 42 m²
(c) 54 m²
(d) 108 m²

Answer 1

(c) 54 m²

Given:
Perimeter of the floor = 2(l + b) = 18 m
Height of the room = 3 m

∴ Area of the four walls = {2(l + b) × h}
= Perimeter × Height
= 18 m × 3 m = 54 m²