MENSURATION
Acknowledgement
We would like to express our special thanks to our Math's
teacher who gave us the golden opportunity to do this
wonderful presentation on the topic ‘Mensuration’. This
helped us in doing a lot of research work and we came to
know about many things, I am really grateful to the
teacher for her constant guidance and support.
Contents
Introduction
Quote—Unquote
Important Terms
Figures
Measuring Plain Figures
Measuring Solid Figures
Review Of Formulae
Group Members
INTRODUCTION
• Mensuration is the branch of geometry which deals with
the measurement of area, length or volume. It is also the
act or process of measuring.
• The Mensuration took its birth in Egypt.
Then it was applied and expanded by great people like
Pythagoras, Euclid, Archimedes, Ptolemy etc and
further developed by Halley, Bernouillies, Euler, Newton
etc.
Quote--Unquote
 Listen to some famous quotes from
famous people about geometry.
 I think the universe is pure geometry-
basically, a beautiful shape twisting
around space-time.
 There is geometry in the humming of
strings, there is music in the spacing of
spheres.
Important Terms
• Solid: A body or geometric figure having three
dimensions.
Important Terms
• Surface Area: The total area of the surface of the three
dimensional figure.
Important Terms
• Perimeter: The continuous line forming the boundary of a
geometrical figure.
Important Terms
• Volume: The total space occupied by an object or the space
inside a container.
Figures
• Plain figures: Plain figures are all about flat 2-
dimensional shapes such as circle, rectangle, etc.
• Solid Figures: Solid Geometry consists of all 3-
dimensional figures like cubes, spheres, etc.
Measuring Plain Figures
 SQUARE :-
• Perimeter of Square: 4 X Side
SIDE
All sides are equal in a
square, therefore
No. of sides= 4
Perimeter= Side X 4
Area of Square: Side X Side
Measuring Plain Figures
 TRIANGLE:-
• Area of Triangle: ½ X base X height
• Perimeter of Triangle: Side +Side +Side
Measuring Plain Figures
 RECTANGLE:-
• Perimeter of Rectangle: 2(length +
breadth)
Opposite sides are equal, hence
» Perimeter= Length+ breadth+
» length+ breadth
» = 2 (length + breadth)
Measuring Solid Figures
 CUBE:-
• Surface Area of Cube: 6 a^2
Number of Faces=6
Area of each face= Side X Side
= a X a
= a^2
Total Area= 6 a^2
• Volume of Cube: Length^3
Volume= Length X Breadth X Height
As the length, breadth and height are
all equal hence
Volume= Length^3
Example
 Let a cube have a side measuring 2 cm.
Find its area as well as volume.
 Side=2 cm
Surface area= 6a^2
= 6(2 X 2)
= 6 X 4
Surface Area= 24 cm^2
2cm
2 cm
Example (Contd.)
Volume= length^3
Length= 2cm
Volume= 2 X 2 X 2
= 8 cm^3
 CUBOID:-
• Surface Area of Cuboid: 2(lb + bh + lh)
Number of Rectangle=6
Area of each rectangle=
length X breadth + length X breadth +
length X height + length X height +
breadth X height + breadth X height
Total Surface Area= 2 (lb + bh + lh)
• Volume of Cuboid= length X breadth X
height
Example
 Let the dimensions of a cuboid be as
follows- l=1 cm, b=2 cm, h=3 cm. Find the
total surface area and volume.
 Surface Area=2(lb+bh+lh)
= 2(1X2 + 2X3 + 1X3)
= 2(2 + 6 + 3)
= 2(11)
= 22 cm^2
1 cm
3cm
2
cm
Example (Contd.)
Volume= length X breadth X height
= 1 X 2 X 3
= 6 cm^3
 Cylinder:-
• Curved Surface Area: 2πrh
When we cut this cylinder along the height
then it will form a rectangle with
dimensions: 2πr and h. This is the
area of
» the curved surface.
» 2πr because, the breadth of the
rectangle= circumference of base’s circle.
r
h
2πr
h
• Total Surface Area: 2πr(r+h)
Total Surface Area = Area of 2 circles
+ Curved Surface Area
TSA= πr^2 + πr^2 + 2πrh
TSA= 2πr^2 + 2πrh
Total Surface Area = 2πr(r+h)
• Volume: πr^2h
r
h
Example
 Let a cylinder have radius=2 cm and
height= 7 cm. Find the TSA, CSA and
volume of the same.
 Radius=2 cm
Height= 7 cm
CSA= 2πrh
= 2 X 22/7 X 2 X 7
= 88 cm^2
7cm
2 cm
Example (Contd.)
TSA= 2πr(r+h)
= 2 X 22/7 X 2(2+7)
= 2 X 22/7 X 18
= 113.14 cm^2
Volume= πr^2h
= 22/7 X (2)^2 X 7
= 22/7 X 4 X 7
= 88 cm^3
 CONE:
• Curved Surface Area: πrs
Radius= r
Slant Height= s
(Cut it along the radius and slant height.)
Area of ABC/ Area of circle with centre C=
Arc length of AB of sector ABC/
Circumference of circle with centre C
Area of ABC/πs^2 = 2πr/2πs = r/s ,
Area of sector ABC = r/s X πs^2
Curved Surface Area = πrs
r
s
A B
C
s
• Total Surface Area:
= Area of Base + Area of curved surface
= πr^2 + πrs
= πr(r+s)
• Volume: 1/3 πr^2h
Example
 Let the radius of the cone be 7 cm and
the slant height be 2 cm. Find it’s CSA,
TSA and volume.
 CSA= πrs
= 22/7 X 7 X 2
= 44 cm^2
TSA= πr(r+s)
= 22/7 X 7(7+2)
7
2
Example (Contd.)
= 22/7 X 7 X 9
= 198 cm^2
Volume= 1/3 πr^2h
= 1/3 X 22/7 X 49 X 2
= 1/3 X 22 X 14
= 1/3 X 308
= 102.66 cm^3
Review Of Formulae
Shapes Perimeter Area Curved
Surface
Area
Total
Surface
Area
Volume
Square 4 X Side Side ^2
Rectangle 2(l + b) Length x
Breadth
Triangle Side+side+
side
½ X b X h
Cube 12a 6a^2 Length^3
Cuboid 4a +4b+ 4c 2(lb+lh+bh) L x b x h
Cone πrs πr(r+s) 1/3πr^2h
Cylinder 2πrh 2πr(r+h) πr^2h
Group Members
 Karan Singh Bora
 Amaan Ahmad
 Vasu Arora
 Tushar Sabhani
 Utsav Garg

Basic Mensuration

  • 1.
  • 2.
    Acknowledgement We would liketo express our special thanks to our Math's teacher who gave us the golden opportunity to do this wonderful presentation on the topic ‘Mensuration’. This helped us in doing a lot of research work and we came to know about many things, I am really grateful to the teacher for her constant guidance and support.
  • 3.
    Contents Introduction Quote—Unquote Important Terms Figures Measuring PlainFigures Measuring Solid Figures Review Of Formulae Group Members
  • 4.
    INTRODUCTION • Mensuration isthe branch of geometry which deals with the measurement of area, length or volume. It is also the act or process of measuring. • The Mensuration took its birth in Egypt. Then it was applied and expanded by great people like Pythagoras, Euclid, Archimedes, Ptolemy etc and further developed by Halley, Bernouillies, Euler, Newton etc.
  • 6.
    Quote--Unquote  Listen tosome famous quotes from famous people about geometry.  I think the universe is pure geometry- basically, a beautiful shape twisting around space-time.  There is geometry in the humming of strings, there is music in the spacing of spheres.
  • 7.
    Important Terms • Solid:A body or geometric figure having three dimensions.
  • 8.
    Important Terms • SurfaceArea: The total area of the surface of the three dimensional figure.
  • 9.
    Important Terms • Perimeter:The continuous line forming the boundary of a geometrical figure.
  • 10.
    Important Terms • Volume:The total space occupied by an object or the space inside a container.
  • 11.
    Figures • Plain figures:Plain figures are all about flat 2- dimensional shapes such as circle, rectangle, etc. • Solid Figures: Solid Geometry consists of all 3- dimensional figures like cubes, spheres, etc.
  • 12.
    Measuring Plain Figures SQUARE :- • Perimeter of Square: 4 X Side SIDE All sides are equal in a square, therefore No. of sides= 4 Perimeter= Side X 4 Area of Square: Side X Side
  • 13.
    Measuring Plain Figures TRIANGLE:- • Area of Triangle: ½ X base X height • Perimeter of Triangle: Side +Side +Side
  • 14.
    Measuring Plain Figures RECTANGLE:- • Perimeter of Rectangle: 2(length + breadth) Opposite sides are equal, hence » Perimeter= Length+ breadth+ » length+ breadth » = 2 (length + breadth)
  • 15.
    Measuring Solid Figures CUBE:- • Surface Area of Cube: 6 a^2 Number of Faces=6 Area of each face= Side X Side = a X a = a^2 Total Area= 6 a^2
  • 16.
    • Volume ofCube: Length^3 Volume= Length X Breadth X Height As the length, breadth and height are all equal hence Volume= Length^3
  • 17.
    Example  Let acube have a side measuring 2 cm. Find its area as well as volume.  Side=2 cm Surface area= 6a^2 = 6(2 X 2) = 6 X 4 Surface Area= 24 cm^2 2cm 2 cm
  • 18.
    Example (Contd.) Volume= length^3 Length=2cm Volume= 2 X 2 X 2 = 8 cm^3
  • 19.
     CUBOID:- • SurfaceArea of Cuboid: 2(lb + bh + lh) Number of Rectangle=6 Area of each rectangle= length X breadth + length X breadth + length X height + length X height + breadth X height + breadth X height Total Surface Area= 2 (lb + bh + lh)
  • 20.
    • Volume ofCuboid= length X breadth X height
  • 21.
    Example  Let thedimensions of a cuboid be as follows- l=1 cm, b=2 cm, h=3 cm. Find the total surface area and volume.  Surface Area=2(lb+bh+lh) = 2(1X2 + 2X3 + 1X3) = 2(2 + 6 + 3) = 2(11) = 22 cm^2 1 cm 3cm 2 cm
  • 22.
    Example (Contd.) Volume= lengthX breadth X height = 1 X 2 X 3 = 6 cm^3
  • 23.
     Cylinder:- • CurvedSurface Area: 2πrh When we cut this cylinder along the height then it will form a rectangle with dimensions: 2πr and h. This is the area of » the curved surface. » 2πr because, the breadth of the rectangle= circumference of base’s circle. r h 2πr h
  • 24.
    • Total SurfaceArea: 2πr(r+h) Total Surface Area = Area of 2 circles + Curved Surface Area TSA= πr^2 + πr^2 + 2πrh TSA= 2πr^2 + 2πrh Total Surface Area = 2πr(r+h) • Volume: πr^2h r h
  • 25.
    Example  Let acylinder have radius=2 cm and height= 7 cm. Find the TSA, CSA and volume of the same.  Radius=2 cm Height= 7 cm CSA= 2πrh = 2 X 22/7 X 2 X 7 = 88 cm^2 7cm 2 cm
  • 26.
    Example (Contd.) TSA= 2πr(r+h) =2 X 22/7 X 2(2+7) = 2 X 22/7 X 18 = 113.14 cm^2 Volume= πr^2h = 22/7 X (2)^2 X 7 = 22/7 X 4 X 7 = 88 cm^3
  • 27.
     CONE: • CurvedSurface Area: πrs Radius= r Slant Height= s (Cut it along the radius and slant height.) Area of ABC/ Area of circle with centre C= Arc length of AB of sector ABC/ Circumference of circle with centre C Area of ABC/πs^2 = 2πr/2πs = r/s , Area of sector ABC = r/s X πs^2 Curved Surface Area = πrs r s A B C s
  • 28.
    • Total SurfaceArea: = Area of Base + Area of curved surface = πr^2 + πrs = πr(r+s) • Volume: 1/3 πr^2h
  • 29.
    Example  Let theradius of the cone be 7 cm and the slant height be 2 cm. Find it’s CSA, TSA and volume.  CSA= πrs = 22/7 X 7 X 2 = 44 cm^2 TSA= πr(r+s) = 22/7 X 7(7+2) 7 2
  • 30.
    Example (Contd.) = 22/7X 7 X 9 = 198 cm^2 Volume= 1/3 πr^2h = 1/3 X 22/7 X 49 X 2 = 1/3 X 22 X 14 = 1/3 X 308 = 102.66 cm^3
  • 31.
    Review Of Formulae ShapesPerimeter Area Curved Surface Area Total Surface Area Volume Square 4 X Side Side ^2 Rectangle 2(l + b) Length x Breadth Triangle Side+side+ side ½ X b X h Cube 12a 6a^2 Length^3 Cuboid 4a +4b+ 4c 2(lb+lh+bh) L x b x h Cone πrs πr(r+s) 1/3πr^2h Cylinder 2πrh 2πr(r+h) πr^2h
  • 32.
    Group Members  KaranSingh Bora  Amaan Ahmad  Vasu Arora  Tushar Sabhani  Utsav Garg