# Chapter 7 Class 9 Triangles (Term 1)

NCERT Solutions of Chapter 7 Class 9 Triangles is available free at teachoo. Solutions to all exercise questions, examples and theorems is provided with video of each and every question.

Let's see what we will learn in this chapter. The topics in the chapter are -

• What is congruency of figures
• Naming of triangles when two triangles are congruent
• What is CPCT - Corresponding Parts of Congruent Triangles
• SAS (Side Angle Side) Congruence Rule (this is without proof)
• ASA (Angle Side Angle) congruence rule with proof (Theorem 7.1)
• Is ASA and AAS congruency the same?
• Angles opposite to equal sides is equal (Isosceles Triangle Property)
• SSS (Side Side Side) congruence rule with proof (Theorem 7.4)
• RHS (Right angle Hypotenuse Side) congruence rule with proof (Theorem 7.5)
• Angle opposite to longer side is larger, and Side opposite to larger angle is longer
• Triangle Inequality - Sum of two sides of a triangle is always greater than the third side

Click on an exercise link below to study from the NCERT Book.

Or click on a Concept link and study the Teachoo way.

Check it out now!