09
Aug
Question 4: ABC is a triangle in which altitudes BE and CF to sides AC and AB are equal (see Fig. 7.32). Show that
(i) △ABE ≅ △ACF
(ii) AB = AC, i.e., ABC is an isosceles triangle.
Chapter 7 – Triangles
This playlist covers all the questions, concepts, theorems and examples of chapter 7 (Triangles) of class 9, NCERT textbook. Click a thumbnail to watch the tutorial.
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Class 9 | Chapter 7 | Example 1 Explanation | NCERT| Congruent Triangles
Congruence v/s Similarity – Explanation of difference between Congruent and Similar with examples
Example 2 – Chapter 7 – Class 9 – Proof of the perpendicular bisector theorem
Class 9 | Chapter 7 | Theorem 7.1 Proof of ASA (Angle Side Angle) Congruence rule | NCERT Maths
Class 9 | Chapter 7 | Example 3 Explanation | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.1, Question 1 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.1, Question 2 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.1, Question 3 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.1, Question 4 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.1, Question 5 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.1, Question 6 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.1, Question 7 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.1, Question 8 Proof | NCERT| Congruent Triangles
Theorem 7.2, Chapter 7, Class 9 – Isosceles triangle theorem – Proof (by 2 different methods)
Theorem 7.3, Chapter 7, Class 9 – Proof | Converse of Isosceles triangle theorem
Class 9 | Chapter 7 | Example 4 Explanation | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Example 5 Explanation | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Example 6 Explanation | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.2, Question 1 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.2, Question 2 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.2, Question 3 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.2, Question 4 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.2, Question 5 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.2, Question 6 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.2, Question 7 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.2, Question 8 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Theorem 7.4 Proof of SSS (Side Side Side) Congruence rule | NCERT Maths
Theorem 7.5, Chapter 7, Class 9 – RHS congruence rule | Theorem | Geometric Proof
Class 9 | Chapter 7 | Example 7 Explanation | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Example 8 Explanation | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.3, Question 1 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.3, Question 2 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.3, Question 3 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.3, Question 4 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Exercise 7.3, Question 5 Proof | NCERT| Congruent Triangles
Class 9 | Chapter 7 | Theorem 7.6 In a triangle, angle opposite to larger side is greater | NCERT
Class 9 | Chapter 7 | Theorem 7.7 In a triangle, side opposite to greater angle is longer | NCERT
Class 9 | Chapter 7 | Theorem 7.8 The sum of any two sides of a triangle is greater than third side
Equal Or Congruent ? Lines and Angles
