types and basics

2. TRIANGLE
 A triangle is a simple closed curved made of
three segments.
 A triangle has three sides and three angles ,
and all three sides and angles are called six
elements of the triangle.
A
CB

3. TYPES OF TRIANGLES ON THE
BASIS OF SIDES
 Scalene triangle-If all the sides of triangle
are unequal they are called scalene triangle.
 Isosceles triangle-If any two sides of a
triangle are
Equal called isosceles triangle.Equal called isosceles triangle.
Equilateral triangle-If all the sides of triangle
are equal it is called equilateral triangle.

4. TYPES OF ANGLES ON THE BASIS OF ANGLES
 Acute angled triangle-If all the three angles of a
triangle are acute it is called acute angled
triangle.
 Right angled triangle-If one angle of a triangle is
a right angle it is called right angled triangle.
 Obtuse angled triangle- if one angle of a triangle
is obtuse it is called obtuse angled triangle.

5. MEDIANS OF A TRIANGLE
 The line segment joining a vertex of a
triangle to the midpoint of the opposite side
is called a median of a triangle.
Altitudes of a triangle
The Perpendicular line segment
from a vertex of a triangle to the
opposite side is called an altitude
of the triangle.

8. PROPERTIES OF A TRIANGLE
Exterior angles of a triangle
An exterior angle + adjacent interior
= 180
An exterior angle of a triangle is equal
to sum of its two interior opposite
angles.

9. ANGLE PROPERTY OF A SPECIAL TRIANGLE
Isosceles triangle
 A triangle in which length of two
sides are equal called isosceles
triangle.triangle.
 In a triangle the angles opposite
sides are equal.

10. EQUILATERAL TRIANGLE
A triangle in which all the
three sides are of equal
length is called an
equilateral triangle.equilateral triangle.
Sum of two sides of triangle
The sum of two sides of the
triangle is greater than
third side