Question

write the identities of surface area and volume​

Answer 1

Step-by-step explanation:

SURFACE AREA OF A CUBOID AND A CUBE

The outer surface of a cuboid is made up of six rectangles. If we take the length of the cuboid as l, breadth as b and the height as h, then

Surface area of a cuboid = 2[lb + bh + hl]

Let us recall that a cuboid whose length, breadth and height are equal is called a cube. Let each edge of the cube be �a', then

Surface area of a cube = 6a2

Note: I. Sometimes a cuboid does not have bottom and top faces. is called the lateral surface area.

II. Lateral surface area of a cuboid is 2(l + b)h.

III. Lateral surface area of a cube is 4a2.

IV. Surface area of a cuboid or cube means total surface area.

Answer 2

Answer:

• Total surface area of a cuboid = 2[lb + bh + lh]

• Total surface area of a cube = 6(side)2

• Lateral surface area of a cuboid = Area of walls of a room = 2(l + b) × h

• Lateral surface area of a cube = 4a2

• Curved surface area of cylinder = 2πrh

• Total surface area of a cylinder = 2πr(r + h)

• Curved surface area of a cone = πrl

• Total surface area of a cone = πr(r + l)

• Surface area of a sphere = 4πr2

• Curved surface area of a hemisphere = 2πr2

• Total surface area of a hemisphere = 3πr2

• Volume of a'cuboid = l × b × h

• Volume of a cube = (side)3

• Volume of a cylinder = πr2rh