Circle
ICSE · Class 9 · Mathematics
Quick revision notes for Circle — ICSE Class 9 Mathematics. Key concepts, formulas, and definitions for last-minute revision.
Key Topics to Revise
Basic Definitions and Components
- A circle is the locus of all points in a plane that are at a fixed distance from a fixed point
- The fixed point is called the centre and the fixed distance is called the radius
- Circumference is the perimeter of the circle
Special Types of Circles and Polygons
- Concentric circles have the same centre but different radii
- Equal or congruent circles have equal radii
- A circumscribed circle passes through all vertices of a polygon
Arcs, Segments, and Sectors
- An arc is a part of the circumference of a circle
- Minor arc is smaller than semicircle, major arc is larger than semicircle
- When both arcs are equal, each is called a semicircle
Chord Properties and Theorems
- Theorem 22: A line from centre to bisect a chord (not diameter) is perpendicular to the chord
- Theorem 23: A perpendicular from centre to a chord bisects the chord
- Greater chord is closer to centre, smaller chord is farther from centre
Get complete notes with diagrams and examples
Full NotesKey Concepts
Get detailed revision notes for Circle
Super Tutor gives you interactive content for every chapter of ICSE Class 9 Mathematics — summaries, quizzes, flashcards, and more.
Try Super Tutor — It's FreeFrequently Asked Questions
What are the important topics in Circle for ICSE Class 9 Mathematics?
Circle covers several key topics that are frequently asked in ICSE Class 9 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.
How to score full marks in Circle — ICSE Class 9 Mathematics?
Start by understanding all key concepts. Practise previous year questions from this chapter. Revise formulas and definitions regularly. Use flashcards for quick revision before the exam.
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More Resources for Circle
Important Questions
Practice with board exam-style questions
Syllabus
What topics to cover
Study Plan
Step-by-step plan to ace this chapter
Flashcards
Quick-fire cards for active recall
Formula Sheet
All formulas in one place
Chapter Summary
Understand the chapter at a glance
Practice Quiz
Test yourself with a quick quiz
Concept Maps
See how topics connect visually