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 » Alternate Segment Theorem

Alternate Segment Theorem

In the following article we are going to know about Alternate Segment Theorem.

Table of Content
  •  

Introduction: 

According to mathematics, A circle is a two-dimensional object in which all points on the circle’s surface are equidistant from the center point. The segment of the circle can be defined as the area between the chord and the arc of the corresponding circle. The circle is the subject of several theorems. 

A circle segment is defined as the area enclosed by an arc and a chord of the circle. Let’s review the definitions of an arc and a circle chord. An arc can be defined as a section of the circumference of a circle. A chord is a section of line that connects any two locations on the circumference of a circle.

A minor segment and a major segment are the two types of segments that exist. A minor arc of the circle creates a minor segment, and a major arc of the circle creates a major segment. Let R be the radius of the arc that forms part of the segment’s perimeter, an area of the segment, c the chord length, s the arc length, h the height of the segment, and θ the central angle subtending the arc in radians.

The chord length and height, as well as the arc length as part of the perimeter, are usually given or measured, while the unknowns are usually the area and sometimes the arc length. Because the radius and central angle cannot be determined directly from chord length and height, two intermediary values, the radius and central angle are commonly calculated first. 

Alternate Segment Theorem:

According to this theorem, The angle created by the tangent and the chord across one of the endpoints is equal to the measure of the angle opposite in the alternate segment.

When a chord is drawn through the point of contact of a tangent to a circle, the angles created by the chord with the given tangent are identical to the angles formed by the corresponding alternate segments.

Assume that a tangent is formed to a circle with P as the point of contact and that a chord PQ is drawn through P at an angle α to the tangent.

Assume that PQ subtends an angle β at any point R along the circle’s circumference, as shown:

The alternate angles in the alternate segment for the angle between the tangent at P and the chord PQ are ∠PRQ = ∠β

 

Regardless of R’s position, this angle will remain constant (as long as R stays in the segment opposite the tangent).

Proof of the Alternate Segment Theorem

The angle formed by the chord and the tangent in the alternate segment is identical to the angle formed by the chord in the first segment.

 

Let’s put this to the test.

Let P be a point on the circle’s circumference. Assume the role of the circle’s center.

Point to Remember:

  • One of the circle theorems is the alternate segment theorem. “For any circle, the angle formed by the chord in the alternate segment is equal to the angle formed by the tangent and the chord across the point of contact of the tangent,” says the theorem. The tangent-chord theorem is another name for the alternate segment theorem.
  • The angle formed by the chord and the tangent is identical to the angle formed by the chord in the other segment, according to the alternate segment theorem.
  • This theorem aids us in determining the unknown angles of any polygon encircled by a circle.
  • The angle measured between a circle chord and a tangent through any of the chord’s endpoints is the same as the angle measured in the alternate segment.
  • A tangent drawn to a circle and a chord drawn from the same point is known as the Alternate Segment Theorem. The angles in the alternate
faq

Frequently asked questions

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

Define what is an alternate angle, In the alternate segment theorem, what is the angle?

Ans: Solution: The alternate angle can be defined as a transversal line that meets two or more parallel lines; we ge...Read full

What is a circle theorem, and how does it work?

Ans : Solution: According to the circle theorem, a perpendicular from the circ...Read full

What is a real-life example of a line segment?

Ans : Solution: A book’s edges create a quadrilateral made up of four-line segments.   ...Read full

What is the alternate interior angle equation?

Ans: Solution: When two angles A and B are the alternate interior angles, they are written as ...Read full

What is the angle segment theorem's alternative name?

Ans: Solution: The tangent-chord theorem is another name for the angle segment theorem.

Ans: Solution: The alternate angle can be defined as a transversal line that meets two or more parallel lines; we get alternate angles that are in opposite locations to the transversal that intersected the lines.

In the alternate segment theorem, the angle can be defined as The angle formed by a chord and a tangent via any of the chord’s endpoints is equal to the angle formed by the alternate segment in a circle, according to the alternate segment theorem.

 

Ans : Solution: According to the circle theorem, a perpendicular from the circle’s center to a chord will always bisect the chord.

 

Ans : Solution: A book’s edges create a quadrilateral made up of four-line segments.

 

 

 

Ans: Solution: When two angles A and B are the alternate interior angles, they are written as ∠A≅∠B. The angle formed by a chord and a tangent via any of the chord’s endpoints is equal to the angle formed by the alternate segment in a circle, according to the alternate segment theorem.

Ans: Solution: The tangent-chord theorem is another name for the angle segment theorem.

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