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Chapter 15 of 22
Revision Notes

Circles

ICSE · Class 10 · Mathematics

Quick revision notes for Circles — ICSE Class 10 Mathematics. Key concepts, formulas, and definitions for last-minute revision.

45 questions22 flashcards5 concepts

Key Topics to Revise

1

Basic Definitions and Properties

  • A circle is the locus of all points in a plane that are at a constant distance from a fixed point called the center
  • The constant distance is called the radius, which is always positive
  • Concentric circles have the same center but different radii
2

Angle Properties of Circles

  • The angle subtended by an arc at the center is double the angle subtended by the same arc at any point on the circle
  • Angles in the same segment of a circle are equal
  • Angle in a semicircle is always a right angle (90°)
3

Cyclic Quadrilaterals

  • A quadrilateral is cyclic if all four vertices lie on a circle
  • Opposite angles of a cyclic quadrilateral sum to 180°
  • If sum of opposite angles of a quadrilateral is 180°, then it is cyclic
4

Tangents and Secants

  • A tangent touches the circle at exactly one point
  • The radius through the point of contact is perpendicular to the tangent
  • From an external point, two tangents can be drawn to a circle

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Full Notes

Key Concepts

The angle subtended by an arcAll angles subtended by the sameAny angle subtended by a diameterIn a cyclic quadrilateral (quadrilateral inscribedA tangent to a circle

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Frequently Asked Questions

What are the important topics in Circles for ICSE Class 10 Mathematics?

Circles covers several key topics that are frequently asked in ICSE Class 10 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.

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.