Access free live classes and tests on the app
Download
+
Unacademy
  • Goals
    • AFCAT
    • AP EAMCET
    • Bank Exam
    • BPSC
    • CA Foundation
    • CAPF
    • CAT
    • CBSE Class 11
    • CBSE Class 12
    • CDS
    • CLAT
    • CSIR UGC
    • GATE
    • IIT JAM
    • JEE
    • Karnataka CET
    • Karnataka PSC
    • Kerala PSC
    • MHT CET
    • MPPSC
    • NDA
    • NEET PG
    • NEET UG
    • NTA UGC
    • Railway Exam
    • SSC
    • TS EAMCET
    • UPSC
    • WBPSC
    • CFA
Login Join for Free
avtar
  • ProfileProfile
  • Settings Settings
  • Refer your friendsRefer your friends
  • Sign outSign out
  • Terms & conditions
  • •
  • Privacy policy
  • About
  • •
  • Careers
  • •
  • Blog

© 2023 Sorting Hat Technologies Pvt Ltd

Watch Free Classes
    • Free courses
    • JEE Main 2024
    • JEE Main 2024 Live Paper Discussion
    • JEE Main Rank Predictor 2024
    • JEE Main College Predictor 2024
    • Stream Predictor
    • JEE Main 2024 Free Mock Test
    • Study Materials
    • Notifications
    • JEE Advanced Syllabus
    • JEE Books
    • JEE Main Question Paper
    • JEE Coaching
    • Downloads
    • JEE Notes & Lectures
    • JEE Daily Videos
    • Difference Between
    • Full Forms
    • Important Formulas
    • Exam Tips
JEE Main 2026 Preparation: Question Papers, Solutions, Mock Tests & Strategy Unacademy » JEE Study Material » Mathematics » Semi Perimeter

Semi Perimeter

The half of a shape's perimeter is referred to as the semi perimeter. The semi perimeter is obtained by dividing the perimeter of a by two.

Table of Content
  •  

In geometry, we may have come across a variety of different types of formulas, such as perimeter, area, height, volume, and other similar terms. When working with polygons, one of the most frequently encountered metrics is the semi perimeter. It is a measurement that is associated with plane figures, which are two-dimensional shapes. Simple formulas can be used to compute the semi perimeter of a variety of various plane figures. In this post, you will discover the definition of semi perimeter, as well as the formula for semi perimeter for various forms, as well as instances of the two terms used.

As we all know, the perimeter of a shape is the distance around it, but the semi perimeter is half the distance around it. The semi perimeter of a given polygon can be computed by dividing its circumference by two for each given polygon. Despite the fact that it is derived from the perimeter in a straightforward manner, the semi perimeter appears frequently in formulas relating to triangles and other shapes, prompting it to be given a separate name. A semi perimeter is represented by the letter “s” in a formula when it is a part of the formula.

 

Semi Perimeter Formula

The formula is Semi perimeter = Perimeter/2.

However, the following table has semi perimeter calculations for a variety of shapes and polygons:

 

Shape

Formula

Explanation

Semi Perimeter of a Triangle formulas

Equilateral triangle

3a/2

a = Length of the side of an equilateral triangle

Isosceles triangle

a + (b/2)

a = Length of congruent sides

b = Length of the third side

Right angle triangle

(base + height + hypotenuse)/2

Height = Perpendicular

Hypotenuse = The longest side

Scalene triangle

(a + b + c)/2

a, b, c are the measures of lengths of three sides

Semi Perimeter of Curved Shapes Formulas

Circle

(2πr)/2 or πr

r = Radius of circle

Semicircle

(πr + 2r)/2

r = Radius of the semicircle

Semi Perimeter of Quadrilaterals Formulas

Rectangle Formula

2(l + b)/2 or l + b

l = Length

b = Breadth

Square

(4a/2) or 2a

a = Side of a square

any quadrilateral

(a + b + c + d)/2

a, b, c, d are the length of sides of the quadrilateral

 

Semi Perimeter of triangle

 

It is possible to calculate the semi perimeter of a triangle by dividing the total perimeter of the triangle by two. Due to the fact that semi’ signifies half, the semi perimeter of a triangle is equal to half the value of the perimeter. In order to determine the area of a triangle using Heron’s formula, the semi perimeter of a triangle must be known. It is possible to express the semi perimeter of a triangle in linear units such as inches, yards, millimetres, and so on. After that, we will go over the formula that is used to calculate the semi-perimeter of a triangular shaped figure. Knowing that the perimeter of a triangle is equal to the sum of the lengths of all its sides, we can calculate its area. Take, for example, a triangle with three equal-length side lengths (a, b and c). The perimeter of the triangle may be computed using this formula: Perimeter = (a+b+c). As a result of using this technique, The semi-perimeter of a triangle is equal to (a + b + c)/2.

 

 

 

Use of the Semi perimeter of Triangle in heron’s formula

When the lengths of all three sides of a triangle are known, the semi perimeter of a triangle can be used to calculate the area of a triangle using Heron’s formula. It is only the lengths of all the triangle’s sides that determine the outcome of this calculation. A semi perimeter is represented by the letter “s,” which is obtained by dividing the perimeter of a triangle by two and is represented by the letter “s.” This is the Heron’s formula, which is written as√[s(s-a)(s-b)(s-c)],  where s denotes the Semi-Perimeter of the triangle and the letters a’, ‘b’, ‘c’ denote the three sides of the triangle. This yields the area of a triangle whose three sides are known in advance of time.

Perimeter of a Semicircle Formula

When calculating the perimeter of a semicircle, the formula for the perimeter of a semicircle is utilised. We must know the diameter or radius of a circle, as well as the length of an arc, in order to solve this problem. In order to get the length of the arc of the semicircle, we must first determine the circumference of a circular figure.

The circumference of a circle is given by the formula C = πd or C = 2πr.

When we take into account the value of C, we can come up with a formula to compute the perimeter of a semicircle, which is determined as the sum of half of a circle’s circumference and the diameter of a circle.

The perimeter of a semicircle is calculated using the formula(πR + d) or (πR + 2R), or R(π + 2)units.

where R = radius of a semicircle

π(pi) is 22/7 or 3.142 and,

d = Diameter of a semicircle.

 Conclusion 

It is possible to calculate the semi perimeter of a triangle by dividing the total perimeter of the triangle by two. Due to the fact that semi’ signifies half, the semi perimeter of a triangle is equal to half the value of the perimeter. In order to determine the area of a triangle using Heron’s formula, the semi perimeter of a triangle must be known.

faq

Frequently asked questions

Get answers to the most common queries related to the JEE Examination Preparation.

What is meant by the term "semi perimeter of triangle"?

Ans. Whenever a triangle has a boundary, the distance around the perimeter fro...Read full

What is indicated by the term "semi-perimeter of a rectangular shape"?

Ans: In geometry, a polygon’s semiperimeter is equal to half of its perimeter, as shown below. Because ...Read full

What is the semi-perimeter of a square?

Ans: As seen in the ‘Smith Diagram’, the semi-perimeter of a squared rectangle is proportional to the nu...Read full

What is the semi-perimeter of a triangle with sides denoted by the letters B and C?

Ans: Semiperimeter =s=2a+b+c

Ans. Whenever a triangle has a boundary, the distance around the perimeter from a vertex to the point on the opposite edge touched by an excircle is equal to the semiperimeter of the triangle. In geometry, a polygon’s semiperimeter is equal to half of its perimeter, as shown below.

Ans: In geometry, a polygon’s semiperimeter is equal to half of its perimeter, as shown below. Because of its straightforward derivation from the perimeter, the semiperimeter appears in enough formulas for triangles and other figures to warrant designation as a separate entity.

 

Ans: As seen in the ‘Smith Diagram’, the semi-perimeter of a squared rectangle is proportional to the number of spanning trees in the rectangle’s semi-perimeter (a planar graph where edges represent squares). The semi-perimeter is represented by a specific number in a specified order, while the square sizes are represented by a different number in the next highest order.

 

Ans: Semiperimeter =s=2a+b+c

Crack IIT JEE with Unacademy

Get subscription and access unlimited live and recorded courses from India’s best educators

  • Structured syllabus
  • Daily live classes
  • Ask doubts
  • Tests & practice
Learn more

Notifications

Get all the important information related to the JEE Exam including the process of application, important calendar dates, eligibility criteria, exam centers etc.

Allotment of Examination Centre
JEE Advanced Eligibility Criteria
JEE Advanced Exam Dates
JEE Advanced Exam Pattern 2023
JEE Advanced Syllabus
JEE Application Fee
JEE Application Process
JEE Eligibility Criteria 2023
JEE Exam Language and Centres
JEE Exam Pattern – Check JEE Paper Pattern 2024
JEE Examination Scheme
JEE Main 2024 Admit Card (OUT) – Steps to Download Session 1 Hall Ticket
JEE Main Application Form
JEE Main Eligibility Criteria 2024
JEE Main Exam Dates
JEE Main Exam Pattern
JEE Main Highlights
JEE Main Paper Analysis
JEE Main Question Paper with Solutions and Answer Keys
JEE Main Result 2022 (Out)
JEE Main Revised Dates
JEE Marking Scheme
JEE Preparation Books 2024 – JEE Best Books (Mains and Advanced)
Online Applications for JEE (Main)-2022 Session 2
Reserved Seats
See all

Related articles

Learn more topics related to Mathematics
Zero Vector

A zero vector is defined as a line segment coincident with its beginning and ending points. Primary Keyword: Zero Vector

ZERO MATRIX

In this article, we will discuss about the zero matrix and it’s properties.

YARDS TO FEET

In this article we will discuss the conversion of yards into feet and feets to yard.

XVI Roman Numeral

In this article we are going to discuss XVI Roman Numerals and its origin.

See all
Access more than

10,505+ courses for IIT JEE

Get subscription

Trending Topics

  • JEE Main 2024
  • JEE Main Rank Predictor 2024
  • JEE Main Mock Test 2024
  • JEE Main 2024 Admit Card
  • JEE Advanced Syllabus
  • JEE Preparation Books
  • JEE Notes
  • JEE Advanced Toppers
  • JEE Advanced 2022 Question Paper
  • JEE Advanced 2022 Answer Key
  • JEE Main Question Paper
  • JEE Main Answer key 2022
  • JEE Main Paper Analysis 2022
  • JEE Main Result
  • JEE Exam Pattern
  • JEE Main Eligibility
  • JEE College predictor
combat_iitjee

Related links

  • JEE Study Materials
  • CNG Full Form
  • Dimensional Formula of Pressure
  • Reimer Tiemann Reaction
  • Vector Triple Product
  • Swarts Reaction
  • Focal length of Convex Lens
  • Root mean square velocities
  • Fehling’s solution
testseries_iitjee
Predict your JEE Rank
.
Company Logo

Unacademy is India’s largest online learning platform. Download our apps to start learning


Starting your preparation?

Call us and we will answer all your questions about learning on Unacademy

Call +91 8585858585

Company
About usShikshodayaCareers
we're hiring
BlogsPrivacy PolicyTerms and Conditions
Help & support
User GuidelinesSite MapRefund PolicyTakedown PolicyGrievance Redressal
Products
Learner appLearner appEducator appEducator appParent appParent app
Popular goals
IIT JEEUPSCSSCCSIR UGC NETNEET UG
Trending exams
GATECATCANTA UGC NETBank Exams
Study material
UPSC Study MaterialNEET UG Study MaterialCA Foundation Study MaterialJEE Study MaterialSSC Study Material

© 2026 Sorting Hat Technologies Pvt Ltd

Unacademy
  • Goals
    • AFCAT
    • AP EAMCET
    • Bank Exam
    • BPSC
    • CA Foundation
    • CAPF
    • CAT
    • CBSE Class 11
    • CBSE Class 12
    • CDS
    • CLAT
    • CSIR UGC
    • GATE
    • IIT JAM
    • JEE
    • Karnataka CET
    • Karnataka PSC
    • Kerala PSC
    • MHT CET
    • MPPSC
    • NDA
    • NEET PG
    • NEET UG
    • NTA UGC
    • Railway Exam
    • SSC
    • TS EAMCET
    • UPSC
    • WBPSC
    • CFA

Share via

COPY