Class 9 Maths Chapter 5 Exercise 5.6 Solutions
Angles Subtended by an Arc
Prepare with complete Exercise 5.6 solutions from Chapter 5 ā Iām Up and Down, and Round and Round based on the latest NCERT Ganita Manjari (2026). This exercise covers arcs, angles subtended by an arc, Theorem 9, angles in the same segment, and the important result for an angle subtended by a diameter. Questions 1, 2 and 3 are explained in a clear, step-by-step CBSE answer-writing style.
Arcs
= 2 Ć Circle Angle
š Table of Contents
š About Class 9 Maths Chapter 5 Exercise 5.6
Class 9 Maths Chapter 5 Exercise 5.6 Solutions cover the sixth exercise of Chapter 5 ā Iām Up and Down, and Round and Round from the latest NCERT Ganita Manjari (2026). This page is designed for students looking for complete, reliable and easy-to-follow NCERT Class 9 Maths solutions arranged according to the exercise questions.
The page presents Exercise 5.6 in a clear, student-friendly CBSE answer-writing format and is useful for classroom practice, homework, self-study, revision and examination preparation. Each question is organised separately so students can quickly find the solution they need.
šÆ Exercise Snapshot
- Complete coverage of Exercise Set 5.6.
- NCERT-based solutions for all three questions.
- Clear, question-wise presentation for Class 9 students.
- Step-by-step NCERT solutions.
- Complete Exercise 5.6 question coverage.
- Simple CBSE answer-writing approach.
- Students following Ganita Manjari (2026).
- Homework and classroom practice.
- Revision and CBSE examination preparation.
š Learn Before You Solve
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angle at a point on the circle,
Theorem 9 ą¤ą¤°
angle in a semicircle ą¤ą„
step-by-step ą¤øą¤®ą¤ą„ą¤ą¤ą„ą„¤
Arc Basics
Understand arcs, their endpoints, and the difference between minor and major arcs.
It is identified by its two points on the circle, called the endpoints, together with the curved part of the circle joining them.
In the figure, A and B are the endpoints.
Here: AXB
Here: AYB
one minor arc and one major arc.
So, whenever a question refers to an arc, first identify which route between the two endpoints is being considered.
Smaller arc ā Minor arc | Larger arc ā Major arc
Angle Subtended by an Arc at the Centre
Understand how a chosen arc of a circle determines an angle at its centre.
The endpoints of the arc are A and B. Join the centre O to A and B.
The angle formed at the centre is:
Minor arc ā smaller central angle | Major arc ā larger central angle
Angle Subtended at a Point on the Circle
See how the same fixed arc can subtend the same angle at suitable points on the circle.
Join each point to the endpoints A and B. We then obtain:
- Fix the arc AKB.
- Choose suitable points P, Q and R on the circle outside the chosen arc.
- Join each point to A and B.
- Measure ā APB, ā AQB and ā ARB.
- Compare the three measured angles.
The angles subtended by this same arc at these suitable points are equal.
šµ Theorem 9
Angle subtended by an arc at the centre and at a point on the circle
Angle at circle = ½ à Angle at centre
Case 1 ā Complete Proof
ā ACB is the angle subtended by arc AFB at the centre C.
D is a point on the circle outside arc AFB.
The extension of DC meets the circle at E on arc AFB.
ā BCA = 2ā BDA
Case 2 ā Extension of DC Meets the Circle at E
Same Arc ā Equal Angles
In the figure, the fixed arc is AXB. Points D, E and F lie on the circle outside this arc.
š Why are the three angles equal?
ā ADB = ā AEB = ā AFB = ½ Ć 100° = 50°
Angle at the centre = 2 Ć angle at the circle
So, for the same arc, every suitable point on the circle gives the same angle.
ā
Same central angle ā ACB
ā
ā ADB = ā AEB = ā AFB = 50°
So do not remember this as simply: āSame chord ā always equal angles.ā
The correct idea is: Same arc + suitable points on the circle ā equal angles.
ā ADB = ā AEB = ā AFB
šµ Corollary ā Angle in a Semicircle
This result is called the angle in a semicircle.
š Why is the angle 90°?
ā ACB = 180°
Therefore,
ā ADB = ½ Ć ā ACB
= 90°
Hence, the angle subtended by a diameter at any point on the circle is a right angle.
Here, the 90° result follows directly from Theorem 9.
Theorem 9 ā Angle at circle = ½ Ć 180°
Therefore ā Angle in a semicircle = 90°
š Same Arc Segment: What Changes and What Does Not?
Let us compare the correct situation with other positions.
When suitable points D, E and F are taken on the circle outside this selected arc, the same arc subtends equal angles:
ā ADB = ā AEB = ā AFB
This is the situation described by Theorem 9: the angle subtended by the same arc at suitable points on the circle remains the same.
The theorem concerns the angle subtended by a specified arc at a point on the circle in the appropriate position relative to that arc.
Therefore, simply seeing the same endpoints A and B is not enough to apply the result.
- Which arc is being considered?
- Where is the vertex of the angle?
- Is the vertex on the circle?
- Is it in the required position outside the selected arc?
ā Correct understanding: āAngles subtended by the same arc at appropriate points on the circle are equal.ā
Always check the arc and the position of the vertex first.
š Concept Connection
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ā” Quick Revision Dashboard
The smaller arc is the minor arc and the larger arc is the major arc.
The angle depends on the arc being swept from OA to OB.
Major arc ā larger central angle
The angle does not depend on which suitable point on the circle is selected.
ā Circle = ½ Ć ā Centre
- ā Same chord always gives equal angles.
- ā Check which arc is being considered.
- ā The vertex must be on the circle.
- ā The point must be in the required position outside the selected arc.
By Theorem 9:
The angle in a semicircle is a right angle.
x = 80°
š Class 9 Maths Chapter 5 Exercise 5.6 Solutions
Solve all three questions of Class 9 Maths Chapter 5 Exercise 5.6 with clear, step-by-step NCERT Ganita Manjari (2026) solutions. This exercise focuses on angles subtended by an arc, Theorem 9, angles in the same arc segment and the important result for an angle subtended by a diameter.
- Are there points X, Y on the circle, on the same side of AB, such that ā AXB is different from ā AYB?
- Is it true that if ā AXB = ā AYB, then X and Y lie on the same side of AB?
- If ā AXB = ā AYB, and X and Y do not lie on the circle, does the circle through A, B and X also pass through Y?
X and Y are points on the circle on the same side of chord AB.
ā AXB = ā AYB.
We have to determine whether X and Y must lie on the same side of AB.
ā AXB = ā AYB
X and Y are points not lying on the circle.
ā AXB = ā AYB.
ā ADC = 100°.
ā ABC = x.
š Continue Learning
Congratulations! You have completed the Class 9 Maths Chapter 5 Exercise 5.6 Solutions. You have now worked through Exercise 5.6 of Chapter 5 ā Iām Up and Down, and Round and Round. Continue your learning journey by moving to the previous or next exercise, or revisiting Exercise 5.6 whenever you need a quick revision.
š Explore More Class 9 Maths Chapters
ā Frequently Asked Questions
Find quick answers to common questions about Class 9 Maths Chapter 5 Exercise 5.6 Solutions. These FAQs help students understand what is covered in the exercise, how the questions are approached, and how to use the solutions effectively for learning, revision, and examination preparation.
What is the main focus of Class 9 Maths Exercise 5.6?
Exercise 5.6 of Class 9 Maths Chapter 5 focuses on angles subtended by an arc. The exercise applies the ideas developed in this part of the chapter, including Theorem 9, angles in the same arc segment, and the special result for an angle subtended by a diameter.
How many questions are there in Exercise 5.6?
There are three questions in Exercise 5.6. Question 2 also contains three parts, so the page presents Question 1, Question 2(i), Question 2(ii), Question 2(iii), and Question 3 separately for easier learning and revision.
What is Theorem 9 in Class 9 Maths Chapter 5?
Theorem 9 states that the angle subtended by an arc at the centre of a circle is double the angle subtended by the same arc at any point on the circle outside the arc. Thus, if the angle at the centre is known, the corresponding angle at the circle is half of it.
What should I know before attempting Exercise 5.6?
Students should be familiar with the basic meaning of an arc, major arc, minor arc, and an angle subtended by an arc at the centre or at a point on the circle. The preceding pages of Chapter 5 also introduce the ideas needed to understand Theorem 9 and its applications.
What is the relationship between the angle at the centre and the angle at the circle?
According to Theorem 9, the angle subtended by an arc at the centre is twice the angle subtended by the same arc at a point on the circle outside the arc. Therefore, angle at the circle = half the angle at the centre.
Why is the angle subtended by a diameter 90°?
A diameter subtends a straight angle of 180° at the centre. By Theorem 9, the angle subtended by the same diameter at any point on the circle is half of this angle: 180° ÷ 2 = 90°. Thus, the angle subtended by a diameter at any point on the circle is 90°.
What does it mean that angles in the same arc segment are equal?
For the same arc, the angles subtended at different suitable points on the circle in the same arc segment are equal. The textbook illustrates this using points on the circle and shows that the corresponding subtended angles have the same measure.
Are these Class 9 Maths Exercise 5.6 Solutions based on Ganita Manjari 2026?
Yes. These Class 9 Maths Chapter 5 Exercise 5.6 Solutions are prepared for the latest NCERT Ganita Manjari (2026) textbook and follow the concepts, terminology, theorem and questions covered in Exercise Set 5.6. The solutions are presented in a student-friendly, step-by-step format for classroom practice, self-study, revision and CBSE examination preparation.
š Useful Learning Resources
Continue your preparation with more Class 9 Maths resources from Maths Gurukulam, or visit the official NCERT and CBSE websites for the latest textbooks, syllabus, and academic updates.
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These Class 9 Maths Chapter 5 Exercise 5.6 Solutions are carefully prepared according to the latest NCERT Ganita Manjari (2026) and the CBSE curriculum. The solutions follow a clear, step-by-step approach to help students understand the questions in Exercise 5.6 and build confidence in solving circle and angle-based problems.