Question

can someone pls send me all the formulae of chapter surface area and volume of class 9th

Answer 1

Cube:-
C.S.A
$4a {}^{2}$
T.S.A
$6a { }^{2}$
Volume
$a {}^{3}$
Hope this will be helpful to u .......
If yes then please make me the brainliest

Answer 2

here is your answer-

SURFACE AREA OF A CUBOID:


Let us consider a cuboid of length = 1 units Breadth = b units and height = h units


Then we have :
(i) Total surface area of the cuboid =2(l * b + b * h + h * l) sq. units
(ii) Lateral surface area of the cuboid = [2 (1 + b)* h] sq. units 
(iii) Area of four walls of a room = [2 (1 + b)* h] sq. units. = (Perimeter of the base * height) sq. units 
(iv) Surface area of four walls and ceiling of a room = lateral surface area of the room + surface area of ceiling =2(1+b)*h+l*b
(v) Diagonal of the cuboid = ?l2 + b2 + h2


SURFACE AREA OF A CUBE :


Consider a cube of edge a unit. 
(i) The Total surface area of the cube = 6a2 sq. units
(ii) Lateral surface area of the cube = 4a2 sq. units.
(iii) The diagonal of the cube = ?3 a units.


SURFACE AREA OF THE RIGHT CIRCULAR CYLINDER


Cylinder: Solids like circular pillars, circular pipes, circular pencils, road rollers and gas cylinders etc. are said to be in cylindrical shapes.


Curved surface area of the cylinder = Area of the rectangular sheet = length * breadth = Perimeter of the base of the cylinder * height = 2?r * h Therefore, curved surface area of a cylinder = 2?rh Total surface area of the cylinder =2?rh + 2?r2 So total area of the cylinder=2?r(r + h)
SURFACE AREA OF A SPHERE


Sphere: A sphere is a three dimensional figure (solid figure) which is made up of all points in the space which lie at a constant distance called the radius, from a fixed point called the centre of the sphere.


Note : A sphere is like the surface of a ball. The word solid sphere is used for the solid whose surface is a sphere.


Surface area of a sphere: The surface area of a sphere of radius r 
= 4 x area of a circle of radius r
= 4 * ?r2 = 4?r2 Surface area ofa hemisphere
= 2?r2 Total surface area of a hemisphere 
= 2?r2 + ?r2 = 3?r2


Total surface area of a hollow hemisphere with inner and outer radius r1 and r2 respectively 
= 2?r2 1 + 2?r2 2 + ?(r2 2 � r2 1) 
= 2?(r2 1 + r2 2) + ?(r2 2 �r2 1)


VOLUMES


VOLUME OF A CUBOID :


Volume : Solid objects occupy space. The measure of this occupied space is called volume of the object.


Capacity of a container : The capacity of an object is the volume of the substance its interior can accommodate.


The unit of measurement of either of the two is cubic unit.


Volume of a cuboid : Volume of a cuboid =Area of the base * height V=l * b * h


So, volume of a cuboid = base area * height = length * breadth * height


Volume of a cube : Volume of a cube = edge * edge * edge
= a3 where a
= edge of the cube


VOLUME OF A CYLINDER


Volume of a cylinder = ?r2h


volume of the hollow cylinder ?r2 2h � ?r2 1h = ?(r2 2 � r2 1)h


VOLUME OF A RIGHT CIRCULAR CONE


volume of a cone = 1 / 3 ?r2h,


where r is the base radius and h is the height of the cone.


VOLUME OF A SPHERE


volume of a sphere the sphere = 4 / 3 ?r3, where r is the radius of the sphere. Volume of a hemisphere = 2 / 3 ?r3


APPLICATION :


Volume of the material of a hollow sphere with inner and outer radii r1 and r2 respectively
= 4 / 3 ?r3 2 � 4 / 3 ?r3 1
= 4 / 3?(r3 2 � r3 1)


Volume of the material of a hemisphere with inner and outer radius r1 and r2 respectively
= 2 / 3?(r3 2 � r3 1)

✌️ HOPE IT HELPS YOU ☺️ .