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Chapter 17 of 28
Chapter Summary

Circle

ICSE · Class 9 · Mathematics

Summary of Circle for ICSE Class 9 Mathematics. Key concepts, important points, and chapter overview.

45 questions20 flashcards5 concepts

Overview

A circle is one of the most fundamental shapes in geometry that we encounter daily in wheels, clocks, coins, and many other objects. This chapter explores the properties, theorems, and relationships of circles, chords, arcs, and related geometric figures. Understanding circles is crucial for advance

Key Concepts

A circle is a closed curve

A circle is a closed curve formed by joining all points in a plane that are at the same fixed distance (radius) from a fixed point (centre). The perim

Points can be classified as

Points can be classified as: (i) Exterior point - distance from centre > radius, (ii) Interior point - distance from centre < radius, (iii) Point on c

Concentric circles have the same centre

Concentric circles have the same centre but different radii. Equal circles have equal radii. Circumscribed circles pass through all vertices of a poly

Arc is part of circumference

Arc is part of circumference. Segment is the region between an arc and its chord. Sector is the region between an arc and two radii. Each can be class

Theorem 22

Theorem 22: A line from the centre bisecting a chord (not diameter) is perpendicular to the chord. Theorem 23: A perpendicular from centre to a chord

Learning Objectives

  • Define a circle and identify its basic components like centre, radius, diameter, and circumference
  • Understand different types of points (interior, exterior, on circumference) in relation to a circle
  • Learn about arcs, segments, and sectors of a circle
  • Master chord properties and their relationships with the centre of the circle
  • Prove and apply important theorems related to chords and their perpendicular bisectors

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Frequently 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.

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.