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Mensuration in Maths | Formulas for 2D and 3D Shapes, Examples

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Mensuration is a branch of mathematics concerned with the calculation of geometric figures and their parameters such as weight, volume, form, surface area, lateral surface area, and so on.

Let’s learn about all the mensuration formulas in maths.

Mensuration Meaning

Mensuration is the branch of mathematics that deals with the measurement of various geometric figures and shapes. This includes calculating areas, volumes, and perimeters of two-dimensional shapes like squares, rectangles, circles, and triangles, as well as three-dimensional figures like cubes, cylinders, spheres, and cones.

These shapes can exist in 2 ways:

  • Two-Dimensional Shapes – circle, triangle, square, etc.
  • Three-Dimensional Shapes – cube, cuboid, cone, etc.

Difference Between 2D and 3D Shapes

2-Dimensional vs 3-Dimensional Shapes

2D Shape3D Shape
Any shape is 2D if it is bound by three or more straight lines in a plane.A shape is a three-dimensional shape if there are several surfaces or planes around it.
There is no height or depth in these shapes.In contrast to 2D forms, these are sometimes known as solid shapes and have height or depth.
These shapes just have length and width as their dimensions.Since they have depth (or height), breadth, and length, they are referred to as three-dimensional objects.
We can calculate their perimeter and area.Their volume, curved surface area, lateral surface area, or total surface area can all be calculated.

Mensuration Terminologies

Here is the list of terms you will come across in mensuration class. We have provided the term, it’s abbreviation, unit and definition for easy understanding.

TermsAbbreviationUnitDefinition
AreaAm2 or cm2The surface that the closed form covers is known as the area.
PerimeterPcm or mA perimeter is the length of the continuous line that encircles the specified figure.
VolumeVcm3 or m3A 3D shape’s space is referred to as its volume.
Curved Surface AreaCSAm2 or cm2The overall area is known as a Curved surface area if there is a curved surface. Example: Sphere
Lateral Surface areaLSAm2 or cm2The term “Lateral Surface area” refers to the combined area of all lateral surfaces that encircle the provided figure.
Total Surface AreaTSAm2 or cm2The total surface area is the total of all the curved and lateral surface areas.
Square Unitm2 or cm2A square unit is the area that a square of side one unit covers.
Cube Unitm3 or cm3The space taken up by a cube with a single side.

Mensuration Formula For 2D Shapes

ShapeArea (Square units)Perimeter (units)Figure
Squarea24a
Square Formula

Square dimensions

Rectanglel × b2 (l + b)
Rectangle Formula

rectangle dimensions

Circleπr22 π r
Circle Formula

circle with radius

Scalene Triangle√[s(s−a)(s−b)(s−c)],
Where, s = (a+b+c)/2
a+b+c
Scalene Triangle Formula

Scalene triangle dimensions

Isosceles Triangle½ × b × h2a + b
Isosceles Triangle

isosceles triangle dimensions

Equilateral triangle(√3/4) × a23a
Equilateral Triangle

Equilateral triangle dimensions

Right Angle Triangle½ × b × h
b + hypotenuse + h
Right Angled Triangle

Right Angle Triangle dimensions

Rhombus½ × d1 × d24 × sideRhombus Formula
Parallelogramb × h2(l+b)
Parallelogram Formula

Parallelogram dimensions

Trapezium½ h(a+c)a+b+c+d
Trapezium Formula

Trapezium dimensions

Learn More:

Mensuration Formula for 3D Shapes

ShapeVolume (Cubic units)Curved Surface Area (CSA) or Lateral Surface Area (LSA) (Square units)Total Surface Area (TSA) (Square units)Figure
Cubea3LSA = 4 a26 a2
Cube

cube dimensions

Cuboidl × b × hLSA = 2h(l + b)2 (lb +bh +hl)
Cuboid

cuboid dimensions

Sphere(4/3) π r34 π r24 π r2
Sphere

sphere dimensions

Hemisphere(⅔) π r32 π r23 π r2
Hemisphere

hemisphere dimensions

Cylinderπ r 2 h2π r h2πrh + 2πr2
Cylinder

cylinder dimensions

Cone(⅓) π r2 hπ r lπr (r + l)Cone

Learn More :

Solved Problems on Mensuration

Let’s solve some example problems on mensuration.

Problem 1: Find the volume of a cone if the radius of its base is 1.5 cm and its perpendicular height is 5 cm.

Solution:

Radius of the cone, r = 1.5 cm

Height of the cone, h = 5 cm

∴ Volume of the cone, V = 13πr2h=13×227×(1.5)2×5= 11.79 cm3

Thus, the volume of the cone is 11.79 cm3

Problem 2: The dimensions of a cuboid are 44 cm, 21 cm, 12 cm. It is melted and a cone of height 24 cm is made. Find the radius of its base.

Solution:

The dimensions of the cuboid are 44 cm, 21 cm and 12 cm.

Let the radius of the cone be r cm.

Height of the cone, h = 24 cm

It is given that cuboid is melted to form a cone.

∴ Volume of metal in cone = Volume of metal in cuboid

⇒(1/3)πr2h=44×21×12             

 (Volume of cuboid=Length×Breadth×Height)

⇒(1/3)×(22/7)×r2×24=44×21×12

⇒r= √(44×21×12×21) / (22×24)

=21 cm

Thus, the radius of the base of cone is 21 cm.
 

Problem 3: The radii of two circular ends of frustum shape bucket are 14 cm and 7 cm. The height of the bucket is 30 cm. How many liters of water can it hold? (1 litre = 1000 cm3).

Solution:

Radius of one circular end, r1 = 14 cm

Radius of other circular end, r2 = 7 cm

Height of the bucket, h = 30 cm

∴ Volume of water in the bucket = Volume of frustum of cone
=(1/3)πh(r12+r1r2+r22)

=13×22/7×30×(142+14×7+72)

=13×22/7×30×343=10780 cm3

=107801000=10.780 L

Thus, the bucket can hold 10.780 litres of water.

FAQs On Mensuration

What is Mensuration?

Mensuration deals with the calculation of geometric figures and their parameters such as weight, volume, form, surface area, lateral surface area, and so on.

What are 2D and 3D Shapes?

Any shape is considered to be 2D if it is bound by three or more straight lines in a plane whereas a shape is a three-dimensional shape if there are several surfaces or planes around it.

What is Area of Cylinder Formula?

Lateral or Curved Surface area of a cylinder = 2π r h

Total Surface Area of a cylinder = 2πrh + 2πr2

What is TSA (Total Surface Area) of Sphere Formula?

Area of Sphere is given by the following formula :

A= 4 π r2

What is Volume of Cone Formula?

Volume of Cone is given by the following formula :

V= (⅓) π r2 h

What is Area of Triangle Formula?

Area of Triangle is given by the following formula :

A= 1/2 ×b ×h

What is Area of Circle Formula?

Area of Circle is given by the following formula :

A= π r2

What is Volume of Cylinder Formula?

Volume of Cylinder is given by the following formula :

V= π r 2 h



Last Updated : 08 Feb, 2024
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