1800-212-7858 (Toll Free) 9:00am - 8:00pm IST all days
Or

Want a call from us
give your mobile number below

Thanks, You will receive a call shortly.
Customer Support

You are very important to us

For any content/service related issues please contact on this toll free number

022-62211530

Mon to Sat - 11 AM to 8 PM

Your cart is empty
MENU
Guided Learning

Afraid of a subject or a topic? Don’t worry, let us know and we will help you master it.

Ok Cancel
Guided Learning
Ok Choose Chapter
Guided Learning
Ok Choose Topic
Guided Learning
Ok Cancel
Guided Learning
Yes No

CBSE Class 9 Maths Triangles

Congruence Criteria: SAS and ASA

Two Geometrical figures are congruent to each other, if they are of the same shape and size.
SAS congruence Axiom: Two triangles are congruent to each other, if any two sides and the included angle of one triangle are equal to the corresponding sides and included angle of the other triangle.
ASA Congruence Rule: Two triangles are congruent, if two angles and the included side of one triangle are equal to the corresponding two angles and the included side of the other triangle. The congruence of triangles also holds even if the side is not included between the angles i.e. AAS holds.

Properties of Isosceles Triangle

The name Isosceles is derived from the Greek word iso (same) and skelos (leg). Two sides of an isosceles triangle are equal in length.
Sides opposite to equal angles of a triangle are equal in length.
Angles opposite to equal sides of a triangle are equal in measure.

Congruence Criteria: SSS and RHS

If all three sides of one triangle are equal to the corresponding three sides of the other triangle, then the two triangles are congruent by S.S.S Congruence Rule.
If in two right triangles the hypotenuse and one side of one right triangle is equal to the hypotenuse and the corresponding side of the other right triangle, then the triangles are congruent by RHS Congruence Rule.

Inequalities in a Triangle

If two sides of a triangle are unequal, then the greater angle is opposite to the greater side.
If two angles of a triangle are unequal, the greater side is opposite to the greater angle
The sum of any two sides of a triangle is greater than the third side.
The difference between any two sides of a triangle is less than the third side.

CBSE Class 9 Revise

Sample Papers and Solutions

Videos

Textbook Solutions

Revision Notes

Syllabus

CBSE Class 9 Tests

Most Important Questions

Multiple Choice Questions

Practice Test

Weekly Test