The perpendicular room is 4m long, 3m wide and 2.5m high. They tiled and painted the interior walls of the room. How many square meters of tiles should be used? Answer only

12m²

Step-by-step explanation:

are the files to be used only for the floor, or also for the walls ? ceiling ?

if it is only for the floor, then the height of the room is irrelevant.

perpendicular clearly stands here for rectangular.

so, the good of the room is a rectangle of 4m length and 3m width.

the area of a rectangle is length×width.

area = 4×3 = 12m²

so, 12m² of tiles will be needed (in reality there would be at least 10% to 20% added for bad tiles, wrong cuts, ...).

if walls need to be included, then you will have to add the areas of 4 more rectangles of length×height.

which would be 2 times 3×2.5 = 7.5m² and 2 times 4×2.5 = 10m².

so, the total area incl. walls would be

12 + 7.5 + 7.5 + 10 + 10 = 47m²

if the ceiling has to be included too, then you need to add the area of another rectangle of the same size as the floor.

so, that total would then be

47 + 12 = 59m².

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)

-7/8

step-by-step explanation:

instead of subtracting you add the -6/8 and -1/8