NCERT Book for Class 9 Mathematics Chapter 7 Triangles
Class 9 Mathematics students should refer to the following NCERT Book chapter Chapter 7 Triangles in standard 9. This NCERT Book for Grade 9 Mathematics will be very useful for exams and help you to score good marks
Chapter 7 Triangles NCERT Book Class 9
You have studied about triangles and their various properties in your earlier classes. You know that a closed figure formed by three intersecting lines is called a triangle. (‘Tri’ means ‘three’). A triangle has three sides, three angles and three vertices. For example, in triangle ABC, denoted as D ABC (see Fig. 7.1); AB, BC, CA are the three sides, Ð A, Ð B, Ð C are the three angles and A, B, C are three vertices. In Chapter 6, you have also studied some properties of triangles. In this chapter, you will study in details about the congruence of triangles, rules of congruence, some more properties of triangles and inequalities in a triangle. You have already verified most of these properties in earlier classes. We will now prove some of them.
7.2 Congruence of Triangles
You must have observed that two copies of your photographs of the same size are identical. Similarly, two bangles of the same size, two ATM cards issued by the same bank are identical. You may recall that on placing a one rupee coin on another minted in the same year, they cover each other completely.
Do you remember what such figures are called? Indeed they are called congruent figures (‘congruent’ means equal in all respects or figures whose shapes and sizes are both the same). Now, draw two circles of the same radius and place one on the other. What do you observe? They cover each other completely and we call them as congruent circles.
Please refer to attached file for NCERT Class 9 Maths Triangles
Books recommended by teachers
NCERT Class 9 Maths Number Systems |
NCERT Class 9 Maths Number Systems Questions |
NCERT Class 9 Maths Polynomials |
NCERT Class 9 Maths Polynomials Questions |
NCERT Class 9 Maths Coordinate Geometry |
NCERT Class 9 Maths Coordinate Geometry Questions |
NCERT Class 9 Maths Linear Equations In Two Variables |
NCERT Class 9 Maths Linear Equations In Two Variables Questions |
NCERT Class 9 Maths Introduction To Euclids Geometry |
NCERT Class 9 Maths Introduction To Euclids Geometry Questions |
NCERT Class 9 Maths Lines And Angles |
NCERT Class 9 Maths Lines And Angles Questions |
NCERT Class 9 Maths Triangles |
NCERT Class 9 Maths Triangles Questions |
NCERT Class 9 Maths Quadrilaterals |
NCERT Class 9 Maths Quadrilaterals Questions |
NCERT Class 9 Maths Areas Of Parallelograms And Triangles |
NCERT Class 9 Maths Areas Of Parallelograms And Triangles Questions |
NCERT Class 9 Maths Circles |
NCERT Class 9 Maths Circles Questions |
NCERT Class 9 Maths Constructions |
NCERT Class 9 Maths Constructions Questions |
NCERT Class 9 Maths Herons Formula |
NCERT Class 9 Maths Herons Formula Questions |
NCERT Class 9 Maths Surface Areas And Volumes |
NCERT Class 9 Maths Surface Areas And Volumes Questions |
NCERT Class 9 Maths Statistics |
NCERT Class 9 Maths Statistics and Probability Questions |
NCERT Class 9 Maths Probability |