Skip to main content
Super TutorResources
Chapter 13 of 22
QuestionsNotesFlashcardsSummaryFormulasQuizConceptsSyllabusPlan
Revision Notes

Similarity

ICSE · Class 10 · Mathematics

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

45 questions22 flashcards5 concepts

Interactive on Super Tutor

Studying Similarity? 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

1,000+ Class 10 students started this chapter today

A comparison illustrating the difference between congruent figures (same shape and size) and similar figures (same shape, different size), using examples of triangles and other polygons.
Super Tutor

Learn better with visuals Super Tutor has hundreds of illustrations like this across every chapter — all free to try.

Get started

Key Topics to Revise

1

Introduction to Similarity

  • Similar figures have the same shape but may have different sizes
  • All congruent figures are similar, but all similar figures are not necessarily congruent
  • Similarity involves proportionality of corresponding parts
2

Criteria for Similarity of Triangles

  • Three main criteria: AA (Angle-Angle), SAS (Side-Angle-Side), SSS (Side-Side-Side)
  • AA Similarity: If two angles of one triangle are equal to two angles of another triangle, the triangles are similar
  • SAS Similarity: If one angle and the two sides including it are proportional to the corresponding angle and sides of another triangle
3

Basic Proportionality Theorem (Thales' Theorem)

  • If a line is drawn parallel to one side of a triangle, it divides the other two sides proportionally
  • Converse: If a line divides two sides of a triangle proportionally, then it is parallel to the third side
  • This theorem is fundamental for proving many similarity relationships
4

Angle Bisector Theorem

  • The internal bisector of an angle in a triangle divides the opposite side in the ratio of the other two sides
  • If AD is the angle bisector of ∠A in triangle ABC, then BD/DC = AB/AC
  • Converse: If a line divides the opposite side in the ratio of the other two sides, then it bisects the angle

Get complete notes with diagrams and examples

Full Notes

Key Concepts

Figures that have the same shapeThree conditions to prove trianglesIf a line is drawn parallelIf a line divides two sidesThe ratio of areas of two

Frequently Asked Questions

What are the important topics in Similarity for ICSE Class 10 Mathematics?
Similarity 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.
How to score full marks in Similarity — ICSE Class 10 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 Similarity

All 22 chapters — ICSE Class 10 Mathematics Revision Notes

For serious students

Get the full Similarity chapter — for free.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for ICSE Class 10 Mathematics.

Try Super Tutor Free
Try the full chapter — Free