Class 10 Triangles Board PYQs Hub
Comprehensive collection of CBSE Class 10 Geometry Chapter 6 Triangles previous year questions. Focus on Basic Proportionality Theorem (Thales' theorem) proofs, similarity criteria (AAA, SAS, SSS), and step-by-step geometric derivations from past 10+ years of board examinations.
Class 10 Chapter 6 Triangles Previous Year Questions
Use this chapter hub to revise Triangles through topic-wise previous year questions. Similarity and the Basic Proportionality Theorem are included in the 2026–27 syllabus; Pythagoras questions below are retained for historical practice and are not in the current syllabus.
Topic-wise PYQ Practice
CBSE Board Exam Blueprint & Topic Weightage: Triangles
In the Class 10 CBSE Board Examination, Triangles is a high-yielding component of Unit 4: Geometry, consistently carrying 8 to 10 marks in the annual 80-mark written board paper. Recurring question formats observed over past board papers include:
- Section A (1 Mark MCQ): Ratio of corresponding sides of similar triangles, ratio of perimeters, and applying AA/SAS similarity criteria in geometric diagrams.
- Section C (3 Marks Theorem Proof): Formal proof of the Basic Proportionality Theorem (BPT / Thales Theorem): if a line is drawn parallel to one side of a triangle, it divides the other two sides in the same ratio.
- Section D / E (4 to 5 Marks Proofs): Higher-order geometric proofs using similarity criteria (AA, SAS, SSS), such as proving diagonals of a trapezium divide proportionally or median ratios in similar triangles.
Key Revision Tips & Common Pitfalls
BPT is one of the most frequently asked 3-mark or 5-mark theorem proofs in CBSE history. Always draw a neat diagram with proper labeling, clearly write Given, To Prove, Construction, and Proof step-by-step with justification in brackets for every statement.