Skip to main content
Super TutorResources
Chapter 11 of 28
Revision Notes

Inequalities — Revision Notes

ICSE · Class 9 · Mathematics

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

28 questions25 flashcards12 formulas & key relations5 concepts

Interactive on Super Tutor

Studying Inequalities? Get the full interactive chapter.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for revision notes and more.

Try Super Tutor — Free

Free trial, no card needed.

A diagram illustrating Theorem 3: If two sides of a triangle are unequal, the greater side has the greater angle opposite to it. Show triangle ABC with AB > AC, and highlight the angles opposite to th
Super Tutor

One of 6 illustrations for Inequalities in Super Tutor — alongside flashcards, concept maps and practice questions.

Key Topics to Revise

1

1. Basic Symbols and Meaning

  • The sign > means is greater than.
  • The sign < means is less than.
  • These symbols are used to compare numbers, lengths, and angles.
2

2. Triangle Side-Angle Relationships

  • If two sides of a triangle are unequal, the greater side has the greater angle opposite to it.
  • If two angles of a triangle are unequal, the greater angle has the greater side opposite to it.
  • These two results are used again and again in proof-based questions.
3

3. Perpendicular from an Outside Point

  • Of all the lines drawn from a point outside a line to that line, the perpendicular is the shortest.
  • In right triangle OPQ, the right angle is the greatest angle.
  • A line drawn from the outside point O to the line AB is shortest when it is perpendicular to AB.
4

4. Triangle Inequality Results

  • The sum of the lengths of any two sides of a triangle is always greater than the third side.
  • The difference between the lengths of any two sides of a triangle is always less than the third side.
  • For triangle ABC, AB + AC > BC, AB + BC > AC, and BC + AC > AB.

Get complete notes with diagrams and examples

Full Notes

Key Concepts

The sign > means is greaterIf two sides of a triangleIf two angles of a triangleOf all the lines drawn fromThe sum of the lengths

Frequently Asked Questions

What are the important topics in Inequalities for ICSE Class 9 Mathematics?
Key topics in Inequalities include Basic Symbols and Meaning, Triangle Side-Angle Relationships, Perpendicular from an Outside Point, Triangle Inequality Results. Study these first, then practise questions on each for Class 9 exams.
How should I revise Inequalities for Class 9 exams?
Learn the core ideas first, then work through the 28 practice questions on Inequalities. 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 Inequalities

All ICSE Class 9 Mathematics Revision Notes

For serious students

Get the full Inequalities chapter — start free.

Quizzes, flashcards, an AI doubt solver and a study plan for ICSE Class 9 Mathematics. Free to start, no card needed.

Try Super Tutor Free
Try this chapter free