Question

anyone Can explain me the intorduction part of Triangles
class 9
plz help
i have maths exam on 6 january plz help ​

Answer 1

Answer:

sorry iam in 7th

Step-by-step explanation:

cant help

Answer 2

Answer:

Congruent Triangles

In a pair of triangles if all three corresponding sides and three corresponding angles are exactly equal, then the triangles are said to be congruent. In congruent triangles, the corresponding parts are equal and are written as CPCT (Corresponding part of the congruent triangle).

Step-by-step explanation:

Triangle

A closed figure with three sides is called a Triangle. It has three vertex, sides and Angles.

Triangle

Types of Triangle

1. There are three types of triangles on the basis of the length of the sides.

Name of Triangle Property Image

Scalene Length of all sides are different Scalene

Isosceles Length of two sides are equal Isosceles

Equilateral Length of all three sides are equal Equilateral

2. There are three types of triangles on the basis of angles.

Name of Triangle Property Image

Acute All the three angles are less than 90° Acute

Obtuse One angle is greater than 90° Obtuse

Right One angle is equal to 90° Right

Congruence

If the shape and size of two figures are same then these are called Congruent.

1. Two circles are congruent if their radii are same.

Two circles are congruent if their radii are same.

2. Two squares are congruent if their sides are equal.

Two squares are congruent if their sides are equal.

Congruence of Triangles

A triangle will be congruent if its corresponding sides and angles are equal.

The symbol of congruent is “≅”.

Congruence of Triangles

AB = DE, BC = EF, AC = DF

m∠A = m∠D, m∠B = m∠E, m∠C = m∠F

Here ∆ABC ≅ ∆DEF

Criteria for Congruence of Triangles

S.No. Rule Meaning Figure

1.

SAS (Side-Angle-Side) Congruence rule

If the two sides and the including angle of one triangle is equal to another triangle then they are called congruent triangles.

SAS Congruence rule

2.

ASA (Angle-Side-Angle) Congruence rule

If the two angles and the including side of one triangle is equal to another triangle then they are called congruent triangles.

ASA Congruence rule

3.

AAS (Angle-Angle-Side) Congruence rule

If any two pairs of angles and a pair of the corresponding side is equal in two triangles then these are called congruent triangles.