2. INTRODUCTION
QUADRILATERAL – A closed figure,in a
plane bounded by four line segments is
called a quadrilateral.
C
D
A B
3. ANGLE SUM PROPERTY OF
QUADRILATERAL
The sum of all the angles of a
quadrilateral is 360°.This can be verified
by drawing a diagonal and dividing a
quadrilateral into two triangles.
D C
A B
5. TRAPEZIUM
A quadrilateral in which one pair of
opposite side is parallel is called a
TRAPEZIUM.
In figure , ABCD is a trapezium because
here ,AB II DC.
A
Parallel sides never meet.
A B
D C
6. PARALLELOGRAM
A quadrilateral in which both pairs of
opposite sides are parallel is called a
PARALLELOGRAM.
In the figure , ABCD is a parallelogram
because ABIIDC and DAIICB.
A B
Indicates equal
sides
D C
7. RECTANGLE
It is a special parallelogram whose one
angle is right angle.
In the figure , ABCD is a rectangle
because ABIICD and ADIIBC and A=90°.
B
Indicates equal sides
Box indicates 900 angle
A
D C
8. RHOMBUS
It is a special parallelogram whose all
sides are equal.
In the figure , ABCD is a rhombus
because ABIICD , ADIIBC and
AB=ABC=CD=DA. B
D C
All four sides are equal
9. SQUARE
It is a special parallelogram in which all
the sides are equal and one angle is right
angle.
In the figure , ABCD is a square because
ABIICD ,ADIIBC and AB=BC=CD=DA and
A=90°. Indicates equal sides
Box indicates 900 angle
10. KITE
A quadrilateral in which two pairs of
adjacent sides are equal is called a KITE.
In the figure , ABCD is a kite because
AD=CD and AB=BC.
Indicates equal
sides
