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Revision Notes

Circle — Revision Notes

ICSE · Class 9 · Mathematics

Circle revision notes for ICSE Class 9 Mathematics: 4 topics in quick points. Part of the ICSE Class 9 Mathematics syllabus.

37 questions24 flashcards2 formulas & key relations5 concepts

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A labeled diagram illustrating the fundamental components of a circle, including the center, radius, diameter, chord, and circumference.
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Key Topics to Revise

1

1. Basic Ideas of a Circle

  • A circle is the figure formed by all points in a plane that are at the same fixed distance from a fixed point.
  • The fixed point is called the centre.
  • The fixed distance is called the radius.
2

2. Position of Points and Types of Circles

  • A point is exterior if its distance from the centre is greater than the radius.
  • A point is interior if its distance from the centre is less than the radius.
  • A point lies on the circumference if its distance from the centre is equal to the radius.
3

3. Arc, Segment and Sector

  • An arc is a part of the circumference.
  • If two arcs are unequal, the smaller arc is the minor arc and the bigger one is the major arc.
  • A minor arc is always smaller than a semicircle.
4

4. Chord Theorems and Distance from the Centre

  • A straight line drawn from the centre to bisect a chord that is not a diameter is perpendicular to the chord.
  • The perpendicular from the centre to a chord bisects the chord.
  • Greater is the size of a chord, smaller is its distance from the centre, and vice-versa.

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Full Notes

Key Concepts

A circle is the setA chord is a line segmentTwo or more circles withAn arc is a partA segment is the part

Frequently Asked Questions

What are the important topics in Circle for ICSE Class 9 Mathematics?
Key topics in Circle include Basic Ideas of a Circle, Position of Points and Types of Circles, Arc, Segment and Sector, Chord Theorems and Distance from the Centre. Study these first, then practise questions on each for Class 9 exams.
How should I revise Circle for Class 9 exams?
Learn the core ideas first, then work through the 37 practice questions on Circle. Revise definitions regularly and use flashcards for quick recall 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

All ICSE Class 9 Mathematics Revision Notes

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