Theorems

Theorem 6.1 - Basic Proportionality Theorem (BPT)
Important

Theorem 6.2 - Converse of Basic Proportionality Theorem

Theorem 6.3

AA Similarity Criteria You are here

Theorem 6.4 Important

Theorem 6.5

Theorem 6.6 Important Deleted for CBSE Board 2025 Exams

Theorem 6.7 Important Deleted for CBSE Board 2025 Exams

Theorem 6.8 Important Deleted for CBSE Board 2025 Exams

Theorem 6.9 Deleted for CBSE Board 2025 Exams

Last updated at April 16, 2024 by Teachoo

AA Criteria If two angles of one triangle are respectively equal to two angles of another triangle, then the two triangles are similar.Given: Two triangles ∆ABC and ∆DEF such that ∠B = ∠E & ∠C = ∠F To Prove: ∆ABC ~ ∆DEF Proof: In ∆ ABC, By angle sum property ∠A + ∠B + ∠C = 180° In ∆ DEF, By angle sum property ∠D + ∠E + ∠F = 180° In ∆ DEF, By angle sum property ∠D + ∠E + ∠F = 180° From (1) and (2) ∠A + ∠B + ∠C = ∠D + ∠E + ∠F ∠A + ∠E + ∠F = ∠D + ∠E + ∠F ∠ A = ∠ D Thus, In Δ ABC & Δ DEF ∠ A = ∠ D ∠ B = ∠ E ∠ C = ∠ F ∴ Δ ABC ~ Δ DEF Hence, proved