Note: The height of the room must be 3 m instead of 3 cm because 3 cm is too small and it cannot be the height of a room.
Given:
Perimeter of the floor of a room = 18 metre
Height of the room = 3 metre
To find:
The area of 4 walls of the room.
Solution:
We know that, the area of 4 walls of the room is the curved surface area of the cuboid room.
The curved surface area of the cuboid is

Where, h is height, l is length and b is breadth.
Perimeter of the rectangular base is 2(l+b). So,

Putting the given values, we get


Therefore, the area of 4 walls of the room is 54 sq. metres.
The answer is D
Because I worked it out
Let
b-----------> the length side of the square box
h------------> the height of the box
SA---------> surface area of the box
we know that
[volume of the box]=b²*h
volume=256 in³
b²*h=256-------> h=256/b²-----> equation 1
surface area of the box=area of the base+perimeter of base*height
area of the base=b²
perimeter of the base=4*b
surface area=b²+(4*b)*h------> SA=b²+4*b*h-----> equation 2
substitute equation 1 in equation 2
SA=b²+4*b*[256/b²]-----> SA=b²+1024/b-----> SA=(b³+1024)/b
the answer is
the formula of the volume of the box is V=b²*h-----> 256=b²*h
the formula of the surface area of the box are
SA=b²+4*b*h
SA=(b³+1024)/b
Answer:idk I’m just a little kid
Step-by-step explanation: