The Triangles and its properties Class 7 PPT

 Page 1


INTRODUCTION
Polygon
Polygon is a simple close curve formed by the line segments is 
called a polygon. Triangle s a polygon with least number of 
lines
Triangle
? A plane figure formed by three non parallel line segment 
is called a triangle
Elements of triangle
? The three sides AB,BC,AC and angle abc,, angle bac and angle 
acb denoted by angle a, angle b and angle c together is known as 
six part of or elements of triangle abc
a
b c
Page 2


INTRODUCTION
Polygon
Polygon is a simple close curve formed by the line segments is 
called a polygon. Triangle s a polygon with least number of 
lines
Triangle
? A plane figure formed by three non parallel line segment 
is called a triangle
Elements of triangle
? The three sides AB,BC,AC and angle abc,, angle bac and angle 
acb denoted by angle a, angle b and angle c together is known as 
six part of or elements of triangle abc
a
b c
TYPES OF TRIANGLES
(BASED ON ITS SIDES)
Page 3


INTRODUCTION
Polygon
Polygon is a simple close curve formed by the line segments is 
called a polygon. Triangle s a polygon with least number of 
lines
Triangle
? A plane figure formed by three non parallel line segment 
is called a triangle
Elements of triangle
? The three sides AB,BC,AC and angle abc,, angle bac and angle 
acb denoted by angle a, angle b and angle c together is known as 
six part of or elements of triangle abc
a
b c
TYPES OF TRIANGLES
(BASED ON ITS SIDES)
EQUILATERAL TRIANGLE
? Equilateral triangle: A triangle with three congruent (equal) 
sides and three equal angles
These marks indicate equality.
A
B
C
Page 4


INTRODUCTION
Polygon
Polygon is a simple close curve formed by the line segments is 
called a polygon. Triangle s a polygon with least number of 
lines
Triangle
? A plane figure formed by three non parallel line segment 
is called a triangle
Elements of triangle
? The three sides AB,BC,AC and angle abc,, angle bac and angle 
acb denoted by angle a, angle b and angle c together is known as 
six part of or elements of triangle abc
a
b c
TYPES OF TRIANGLES
(BASED ON ITS SIDES)
EQUILATERAL TRIANGLE
? Equilateral triangle: A triangle with three congruent (equal) 
sides and three equal angles
These marks indicate equality.
A
B
C
ISOSCELES TRIANGLES
? At least two sides are the same length
5
A
B C
Page 5


INTRODUCTION
Polygon
Polygon is a simple close curve formed by the line segments is 
called a polygon. Triangle s a polygon with least number of 
lines
Triangle
? A plane figure formed by three non parallel line segment 
is called a triangle
Elements of triangle
? The three sides AB,BC,AC and angle abc,, angle bac and angle 
acb denoted by angle a, angle b and angle c together is known as 
six part of or elements of triangle abc
a
b c
TYPES OF TRIANGLES
(BASED ON ITS SIDES)
EQUILATERAL TRIANGLE
? Equilateral triangle: A triangle with three congruent (equal) 
sides and three equal angles
These marks indicate equality.
A
B
C
ISOSCELES TRIANGLES
? At least two sides are the same length
5
A
B C
SCALENE TRIANGLES 
? Scalene triangle: A triangle that has no congruent (equal) 
sides
A
B
C