Access the official NCERT Class 10 Mathematics textbook for Chapter 6 – Triangles PDF. This chapter builds on Class IX congruence and introduces similarity of figures, focusing on triangles. It covers criteria for triangle similarity (AA, SSS, SAS), the Basic Proportionality Theorem (Thales’ theorem) and its converse, Pythagoras’ theorem, and extends similarity to area relationships—essential for solving indirect measurement problems like determining heights using shadows.
Chapter Highlights:
- Similar vs Congruent Figures: Understanding shape vs size
- Criteria for Similarity in Triangles: AA, SSS, SAS
- Basic Proportionality Theorem (Thales’ theorem) & Converse
- Applications of Similarity: Indirect measurements & real-life problems
- Pythagoras’ Theorem: Proof and converse in right-angled triangles
- Areas of Similar Triangles: Area ratio = square of side ratio