A ppt on the surface area and volume of a cone with examples and good definitions which leads to a better understanding........

1. Surface Area and Volumes
CONE

2.  A Cone is a three dimensional solid with a circular base and a
curved surface that gradually narrows to a vertex.
 We are going to learn about how can we find the surface area
and volume of a right cone (a cone whose vertex is
perpendicular as well as in center in accordance with the
base.

3.  Any 3D solid is made up of flat or curved surfaces called
as face of the surface.
 These surfaces are 2D and enclose an area.
 The area of all faces together gives the Surface Area of
the given solids.

4.  A cone has a circular base and a vertex that is not in the same plane as a
base.
 In a right cone, the height meets the base at its center.
 The height of a cone is the perpendicular distance between the vertex and
the base.
 The slant height of a cone is the distance between the vertex and a point
on the base edge.

5.  Surface Area = area of base
+ area of sector
= area of base + π(radius of
base)*(slant height)
= πr(r+l)
Lateral surface area is the
surface area of all sides
but excluding the base.
Since Lateral Area
=Surface Area – area
of the base
= πr2 + πrl - πr2
= πrl

6.  The space occupied by a 3D object is
called
‘Capacity of that object’ or volume.

7.  3 cones fill the cylinder, so…
 Volume = ⅓ Base x height

8.  3 cones fill the cylinder
 Therefore, 3*volume of cone =
volume of cylinder
 V of cylinder=r2h
 V of cone = r2h/3
OR
 Volume = ⅓ Base x height
 V=BH/3
 Base area = r2
 V= ⅓ r2h
r =2.5 cm
h = 7 cm

9.  In a cone, h=3 cm, l=4cm and d=14 cm. Find out the
T.S.A., L.S.A. and volume.
Ans.)
T.S.A.= r(r+l)= (22/7)*7(7+4) = 22*11 = 242 sq. cm.
L.S.A.= rl = (22/7)*7*4 = 22*4 = 88 sq. cm.
Volume = (r2h)/3 = {(22/7)*7*7*3}/3 = 22*7 = 154
cubic cm.

10. Vanchhit
Anjali
Astha
Diksha
Hitansh
Jainesh
Nitya
Prachi