The document defines and describes different types of triangles. It introduces triangles as a closed figure with three line segments. It then defines and provides examples of acute, obtuse, equilateral, isosceles, and scalene triangles. The document also outlines some general properties of all triangles, such as the sum of interior angles equaling 180 degrees and exterior angles summing to 360 degrees.

1. WELCOME
           
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 1

2. TRIANGLE
PRESENTED BY:
TARUN MAHAJAN
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 2

3. WHAT IS TRIANGLE?
A closed figure consisting of three line
segments linked end-to-end.
Altitude
Base
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 3

4. TYPES OF TRIANGLE
Acute Triangle
Obtuse Triangle
Equilateral Triangle
Isosceles Triangle
Scalene Triangle
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 4

5. ACUTE TRIANGLE
A triangle in which all three angles are acute
angles (less than 90 degree).
As shown in the diagram below. Here all the
angles are less than 90 degree and hence, it
is an Acute Triangle.A
B C
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 5

6. OBTUSE TRIANGLE
A triangle in which one of the angles is an
obtuse angle(more than 90 degree).
As shown in the diagram below. Here angle C
is more than 90 degree and hence, it is an
Obtuse Triangle .
C
A B
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 6

7. EQUILATERAL TRIANGLE
A triangle in which all three sides are of equal length.
It is also called regular triangle. An Equilateral
Triangle is special case of an Isosceles Triangle with
all three sides equal. In the diagram below, each
side is of equal length a and each angle is of equal
measure A.
C
A B
a
a
a
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 7

8. ISOSCELES TRIANGLE
A triangle in with (at least) two sides are equal.
Angles opposite to equal side lengths are
equal.
In the diagram below, the two equal sides have
length b and the remaining side has length c.
Hence, Angle A and B are equal.
C
A B
b b
c
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 8

9. SCALENE TRIANGLE
A triangle in which all three sides are of
unequal lengths. As shown in the diagram
below
C
A B
ab
c
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 9

10. PROPERTIES OF ALL TRIANGLES:
These are some well known properties of all
triangles. The interior angles of a triangle
always add up to 180°
The exterior angles of a triangle always add up
to 360°
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 10

11. PRESNETED BY
TARUN MAHAJAN
THE END
W EDNESDAY, AUGUST 21,
2013CREATED BY TARUN MAHAJAN 11