Maths project surface area and volume by chirag jain class ix a roll no. 17
The document presents an introduction to different geometric shapes including cubes, cuboids, cylinders, cones, spheres, and hemispheres, focusing on their surface areas and volumes. It explains the calculations for total surface area and volume for each shape with relevant formulas. Real-life applications of these geometric concepts, such as gift wrapping and filling containers, are also highlighted.
INTRODUCTION
CUBE
CUBOID
RIGHT CIRCULAR CYLINDER
RIGHT CIRCULAR CONE
SPHERE
HEMISPHERE
14.
Have youever wrapped a birthday gift?
If so, then you've covered the surface
area of a polyhedron with wrapping
paper.
Have you ever poured a glass of milk?
If so, then you've filled the volume of a
glass with milk.
Not only this, but in day-to-day life, we
come across many activities which
involve the concept of surface areas and
volume.
15.
Surface Areaof an object refers to the
total area of all its surfaces.
For example : The amount of paper
required to wrap a gift gives us an idea
of surface area of gift.
16.
Volume ofa solid
object refers to the
amount of space it
occupies or
contains.
For example : The
amount of water a
swimming pool can
hold gives us an
idea of the volume
of the swimming
pool.
18.
SURFACE
AREAIf each edgeof cube is a units, its
Total surface area = 6a2 sq. units
Area of the faces leaving the top
And the bottom ones is known as
Its L.S.A. (Lateral Surface Area).
L.S.A. of cube = 4a2 sq. units
VOLUME
Volume of acuboid =
Length × Breadth × Height
Or
V = l × b × h
Where, V = volume
l = length, b = breadth
h = height
25.
WHAT IS ARIGHT
CIRCULAR
CYLINDER ? A cylinder is a
right circular
cylinder if :
Its base is a
circle and
Radius of the
base is
perpendicular to
its height.
26.
SURFACE AREA
C.S.A.of
cylinder
= Area of
rectangular
sheet
= 2πrh
o T.S.A. of cylinder
= C.S.A. + Lid
area + Base
area
2
WHAT IS ARIGHT
CIRCULAR CONE?
In a right circular
cone, the radius
of the circular
base is
perpendicular to
its height.
Also, Slant
Height
l =
Height h
Base
r
Slant Height
l
30.
CURVED SURFACE
AREA
l l
2πr
r
Areaof sector = Circumference of arc
Area of circle Circumference of circle
Area of sector = 2πr × πl 2 = πrl
2πl
C.S.A. of cone = Area of sector = πrl