Advertisements
Advertisements
प्रश्न
If the length of a diagonal of a cube is `8 sqrt(3)` cm, then its surface area is
विकल्प
512 cm2
384 cm2
192 cm2
768 cm2
उत्तर
Let,
a→ Side of the cube
Length of the diagonal = 8`sqrt(3) ` cm
`sqrt(3a) = 8 sqrt(3)`
a = 8 cm
We have to find the surface area of the cube
Surface area of the cube,
`=6a^2`
`=6xx8^2`
`=384 cm^2`
Thus, surface area of the cube is 384 cm2 .
APPEARS IN
संबंधित प्रश्न
The dimensions of a room are 12.5 m by 9 m by 7 m. There are 2 doors and 4 windows in the room; each door measures 2.5 m by 1 .2 m and each window 1 .5 m by I m. Find the cost of painting the walls at Rs. 3.50 per square metre.
A cuboidal vessel is 10 cm long and 5 cm wide. How high it must be made to hold 300 cm3 of a liquid?
A water tank is 3 m long, 2 m broad and 1 m deep. How many litres of water can it hold?
Find the surface area of a cuboid whose length = 6 dm, breadth = 8 dm, height = 10 dm.
Show that the product of the areas of the floor and two adjacent walls of a cuboid is the square of its volume.
The walls and ceiling of a room are to be plastered. The length, breadth and height of the room are 4.5 m, 3 m and 350 cm, respectively. Find the cost of plastering at the rate of Rs 8 per square metre.
The length, breadth, and height of a room are 6 m, 5.4 m, and 4 m respectively. Find the area of :
(i) its four-walls
(ii) its roof.
The ratio between the curved surface area and the total surface area of a cylinder is 1: 2. Find the ratio between the height and the radius of the cylinder.
A room is 5m long, 2m broad and 4m high. Calculate the number of persons it can accommodate if each person needs 0.16m3 of air.
The dimensions of a cuboidal box are 6 m × 400 cm × 1.5 m. Find the cost of painting its entire outer surface at the rate of ₹ 22 per m2.