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Mensuration – Definition, Formulas, Examples & FAQs for Easy Learning
IMPORTANT LINKS
Mensuration is the part of math that helps us measure shapes and objects around us.
It tells us how to find things like length, area, volume, and surface area for different figures—like squares, rectangles, circles, cubes, and cylinders.
We use it in real life too, like when we want to know how much space is inside a box or how much paint we need to cover a wall.
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Table of Contents:
Mensuration Maths- Definition
Mensuration is a part of math that helps us measure the length, area, or volume of different shapes. These shapes can be flat (2D), like squares and circles, or solid (3D), like cubes and cylinders. Mensuration tells us how much space a shape covers or holds. In this topic, we learn how to work with both 2D and 3D shapes using simple formulas to find their measurements.
Differences Between 2D and 3D shapes
2D Shape |
3D Shape |
A 2D shape is defined by three or more straight lines on a plane. |
A 3D shape is defined by multiple surfaces or planes. |
2D shapes lack depth or height. |
3D shapes, also known as solid shapes, have height or depth. |
2D shapes only have two dimensions, namely length and breadth. |
3D shapes have three dimensions: depth (or height), breadth, and length. |
Their area and Perimeter can be measured. |
Their volume, Curved Surface Area (CSA), Lateral Surface Area (LSA), or Total Surface Area (TSA) can be measured. |
Mensuration in Maths- Important Terminologies
Let’s familiarize ourselves with a few more definitions associated with this subject.
Terms |
Abbreviation |
Unit |
Definition |
Area |
A |
m2 or cm2 |
The area refers to the surface covered by a closed shape. |
Perimeter |
P |
cm or m |
The perimeter is the measure of the continuous line along the boundary of a given figure. |
Volume |
V |
cm3 or m3 |
The volume is the space occupied by a 3D shape. |
Curved Surface Area |
CSA |
m2 or cm2 |
The Curved Surface area is the total area of a curved surface, such as a sphere. |
Lateral Surface area |
LSA |
m2 or cm2 |
The Lateral Surface area is the total area of all the lateral surfaces that surround a given figure. |
Total Surface Area |
TSA |
m2 or cm2 |
The Total Surface area is the sum of all the curved and lateral surface areas. |
Square Unit |
– |
m2 or cm2 |
A Square unit is the area covered by a square with sides of one unit. |
Cube Unit |
– |
m3 or cm3 |
A Cube unit is the volume occupied by a cube with sides of one unit. |
Mensuration Formulas
Now let’s delve into all the essential mensuration formulas for 2D and 3D shapes. These formulas will help you solve mensuration problems with ease. The most common formulas in mensuration typically involve the surface area and volumes of 2D and 3D figures.
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Mensuration Formulas For 2D Shapes
Below, you’ll find the mensuration formulas for two-dimensional geometric shapes.
Shape |
Area (Square units) |
Perimeter (units) |
Figure |
Square |
a2 |
4a |
|
Rectangle |
l × b |
2 ( l + b) |
|
Circle |
πr2 |
2 π r |
|
Scalene Triangle |
√[s(s−a)(s−b)(s−c)], Where, s = (a+b+c)/2 |
a+b+c |
|
Isosceles Triangle |
½ × b × h |
2a + b |
|
Equilateral triangle |
(√3/4) × a2 |
3a |
|
Right Angle Triangle |
½ × b × h |
b + hypotenuse + h |
|
Rhombus |
½ × d1 × d2 |
4 × side |
|
Parallelogram |
b × h |
2(l+b) |
|
Trapezium |
½ h(a+c) |
a+b+c+d |
Mensuration Formulas for 3D Shapes
Here are the mensuration formulas for three-dimensional shapes in geometry.
Shape |
Volume (Cubic units) |
Curved Surface Area (CSA) or Lateral Surface Area (LSA) (Square units) |
Total Surface Area (TSA) (Square units) |
Figure |
Cube |
a3 |
LSA = 4 a2 |
6 a2 |
|
Cuboid |
l × b × h |
LSA = 2h(l + b) |
2 (lb +bh +hl) |
|
Sphere |
(4/3) π r3 |
4 π r2 |
4 π r2 |
|
Hemisphere |
(⅔) π r3 |
2 π r2 |
3 π r2 |
|
Cylinder |
π r2 h |
2π r h |
2πrh + 2πr2 |
|
Cone |
(⅓) π r2 h |
π r l |
πr (r + l) |
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Mensuration Solved Problems
Question 1:
Find the area and perimeter of a rectangle with length 8 cm and width 4 cm.
Solution:
Given:
Length = 8 cm
Width = 4 cm
Area of rectangle = length × width
= 8 × 4 = 32 cm²
Perimeter of rectangle = 2 × (length + width)
= 2 × (8 + 4) = 2 × 12 = 24 cm
Answer:
Area = 32 cm², Perimeter = 24 cm
Question 2:
Find the area of a triangle with base 10 cm and height 6 cm.
Solution:
Given:
Base = 10 cm
Height = 6 cm
Area of triangle = (1/2) × base × height
= (1/2) × 10 × 6 = 30 cm²
Answer:
Area = 30 cm²
Question 3:
Find the circumference and area of a circle with radius 7 cm.
Solution:
Given:
Radius (r) = 7 cm
Circumference = 2πr
= 2 × (22/7) × 7 = 44 cm
Area = πr²
= (22/7) × 7 × 7 = 154 cm²
Answer:
Circumference = 44 cm, Area = 154 cm²
Question 4:
Find the diagonal of a square with side length 6 cm.
Solution:
Given:
Side (a) = 6 cm
Diagonal of square = a√2
= 6√2 cm
Answer:
Diagonal = 6√2 cm
Practice Questions
1.Find the area of a rectangle with Length = 15 cm,Breadth = 12 cm.
2.Calculate the volume of a right circular cylinder with Radius = 7 cmHeight = 24 cm.
3.Find the curved surface area (CSA) of a cylinder with Radius = 5 cmHeight = 10 cm.
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Frequently Asked Questions For Mensuration
What is Mensuration?
Mensuration is a branch of mathematics that deals with the measurement of length, area, and volume of different 2D and 3D shapes such as squares, rectangles, circles, cubes, cuboids, cylinders, cones, and spheres.
What are the types of mensuration?
2D Mensuration – deals with flat shapes (area, perimeter). 3D Mensuration – deals with solid shapes (surface area, volume).
What is 2D mensuration used for?
2D mensuration is used to calculate area (the space inside a shape) and perimeter (the boundary length) of flat figures like rectangles, circles, and triangles. Example: finding how much land a farmer owns.
What is 3D mensuration used for?
3D mensuration is used to measure volume (how much space an object occupies) and surface area (how much material is needed to cover it). Example: finding the capacity of a water tank.
What is the formula for the perimeter of a circle?
The perimeter of a circle is called the circumference, and its formula is: 2 × π × radius (π = 3.14)
How do you find the surface area of a cube?
Surface area of a cube = 6 × side²
What is the volume of a cylinder?
Volume of a cylinder = π × radius² × height