Skip to main content
Super TutorResources
Chapter 7 of 12
QuestionsNotesFlashcardsSummaryFormulasQuizConceptsSyllabusPlan
Revision Notes

Triangles

Uttar Pradesh Board · Class 9 · Mathematics

Quick revision notes for Triangles — Uttar Pradesh Board Class 9 Mathematics. Key concepts, formulas, and definitions for last-minute revision.

41 questions22 flashcards5 concepts

Interactive on Super Tutor

Studying Triangles? 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 9 students started this chapter today

A labeled diagram showing a triangle with its three sides, three angles, and three vertices clearly marked.
Super Tutor

Super Tutor has 16+ illustrations like this for Triangles alone — flashcards, concept maps, and step-by-step visuals.

See them all

Key Topics to Revise

1

Congruence of Triangles

  • Two figures are congruent if they have the same shape and size
  • Congruent triangles can be placed on each other to cover completely
  • When ΔABC ≅ ΔPQR, corresponding parts are equal (CPCT)
2

Criteria for Congruence of Triangles

  • One side or one angle equality is not sufficient for congruence
  • SAS (Side-Angle-Side): Two sides and included angle must be equal
  • ASA (Angle-Side-Angle): Two angles and included side must be equal
3

Properties of Isosceles Triangles

  • Isosceles triangle has two equal sides
  • Angles opposite to equal sides are equal (base angles)
  • Converse: If two angles are equal, opposite sides are equal
4

Proof Techniques and Applications

  • ASA theorem proof uses SAS axiom
  • Construction method for proving SSS congruence
  • Indirect proof method (assuming opposite)

Get complete notes with diagrams and examples

Full Notes

Key Concepts

Two figures are congruent if theyTwo triangles are congruent if twoTwo triangles are congruent if twoTwo triangles are congruent if anyTwo triangles are congruent if all

Frequently Asked Questions

What are the important topics in Triangles for Uttar Pradesh Board Class 9 Mathematics?
Triangles covers several key topics that are frequently asked in Uttar Pradesh Board Class 9 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.
How to score full marks in Triangles — Uttar Pradesh Board Class 9 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 Triangles

All 12 chapters — Uttar Pradesh Board Class 9 Mathematics Revision Notes

For serious students

Get the full Triangles chapter — for free.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for Uttar Pradesh Board Class 9 Mathematics.

Try Super Tutor Free
Try the full chapter — Free