1. Triangles and Types of Triangles
Std. :- 6th
Sub. :- Mathematics
Chapter no. 20
Triangles and Types of Triangles

2. L M N S T D D E F
Name of the triangle
Name if its vertices
Name of its three sides
Name of its angels
STD

3. . . .P . . . .D .Q . A L O S M U C B N Points on triangle
Name of the triangle
Interior points
Exterior Points S . M . U .D C B .Q . N

4. An exterior angle of a triangle
An angle that forms a linear pair with an angle of a triangle is called an exterior angle of the triangle . . z W Y

5. Different Types of Triangles
There are several different types of triangles.
You can classify a triangle by its sides and its angles.
There are THREE different classifications for triangles based on their sides.
There are FOUR different classifications for triangles based on their angles.

6. Classifying Triangles by Their Sides
EQUILATERAL – 3 congruent sides
ISOSCELES – at least two sides
congruent
SCALENE – no sides congruent
EQUILATERAL
ISOSCELES
SCALENE

7. Classifying Triangles by Their Angles
ACUTE – all angles are acute
RIGHT – one right angle
OBTUSE – one obtuse angle
ACUTE
RIGHT
OBTUSE

8. An acute angled triangle.
If all angles of a triangle are acute then the triangle is called acute angled triangle.

9. Can You Classify the Different Triangles in the Picture Below?
Classify the following triangles: AED, ABC, ACD, ACE

10. The Classifications… Triangle AED = Equilateral
Triangle ABC = Equilateral
Triangle ACD = Isosceles, Obtuse
Triangle ACE = Scalene, Right