must seee sure u will like it

2. We all gratefully acknowledge the valuable
contributions of our respected MATHS TEACHER as
without her we won`t be able to prepare this
PowerPoint presentation of Maths.
Our special thanks for her support
and her precious knowledge that made us able to
accomplish this task.

3. A Quadrilateral is an enclosed 4 sided figure which has 4
vertices and 4 angles.
There are two types of quadrilaterals and they are:-
 Convex quadrilateral:-
A quadrilateral whose all four angles sum upto 360 degree
and diagonals intersect interior to it
 Concave quadrilateral:-
A quadrilateral whose sum of four angles is more than 360
degrees and diagonals intersect interior to it.
 There are many types of quadrilaterals which have
many different properties.

5. A quadrilateral with opposite sides parallel and
equal is a parallelogram .
Properties:-
• A diagonal of a parallelogram divides it into
two congruent triangles.
•In a parallelogram, opposite sides are equal.
•In a parallelogram opposite angles are equal.
•The diagonals of a parallelogram bisect each
other.
These properties have their converse also.

6. A rectangle is a parallelogram with one angle 90 degree
The properties of rectangle are:-
The diagonals of rectangle are of equal length.
It has including properties of parallelogram.
It has two pairs of opposite sides equal.
The opposite sides of rectangle are parallel to each other.

7. A square is a rectangle with adjacent sides
equal. The properties of a square are:-
Square has including properties of
Rectangle
Diagonals of a
square bisect each other at 90
Degrees and are equal.
The all four interior angles of square are
right angles.

8. A Rhombus is a parallelogram with adjacent
sides equal. The properties of rhombus are:-
A rhombus has the including properties of
A parallelogram.
The diagonals of rhombus bisect each other at 90 degree
The diagonals of rhombus bisect opposite angles

9. A trapezium is quadrilateral with one pair of opposite sides parallel and
other sides are non parallel
PROPERTIES OF TRAPEZIUM ARE:-
Co-interior angles of parallel sides of trapezium are supplementary
Sum of the angles of trapezium are 360 degree.

10. A quadrilateral with two pairs of adjacent sides
equal is known as a kite. Properties of kite are:-
The diagonals of a kite bisect each other 90
degree.
Adjacent sides of a kite are equal.
The smaller diagonal bisect the angles of kite.
Sum of angles of kite is 360 degree.

11. The line segment joining the mid point of two
sides of a triangle is always parallel to the
third side and half of it.

12. Given:-D and E are the mid points of the sides AB
and AC .
To prove:-DE is parallel to BC and DE is half of
BC.
construction:- Construct a line parallel to AB
through C.
proof:-in triangle ADE and triangle CFE
AE=CE
angle DAE= angle FCE (alternate angles )
angle AED= angle FEC (vertically opposite

13. Hence by CPCT AD= CF- - - - - - - - -1
But
AD = BD(GIVEN)
so from (1), we get,
BD = CF
BD is parallel to CF
Therefore BDFC is a parallelogram
That is:- DF is parallel to BC and DF= BC
Since E is the mid point of DF
DE= half of BC, and , DE is parallel to BC
Hence proved .

14. According to the converse of mid point theorem
the line drawn through the mid point of one side
of a triangle, is parallel to another side bisects the
third side.
WE CAN PROVE THE CONVERSE OF
THE MID POINT THEOROM THROUGH
THE EXPLANATION IN THE NEXT SLIDE .

15. and EF is half of BC