Question

the area of four walls of a room is 120 m square if the length of the room is twice its breadth and the height is 4 m find the area of the floor

Answer 1

Lateral surface area = 120m²
let the breadth be x
length = 2x
height = 4m

Lateral surface area = 2 h ( l + b )
120 = 2×4( x +2x )
$\frac{120}{8} = 3x$
3x = 15

$x = \frac{15}{3}$
x = 5

length = 2x = 2 × 5 = 10m
breadth = x = 5m

area of the floor = length × breadth
= 10m × 5m

= 50m²