1. Quad
rilat
erals

2. WHAT IS A QUADRILATERAL?
 Any figure with four vertices and four sides is
known as a quadrilateral.
 For e.g.:-
 Parallelogram
 Rectangle
 Square
 Trapezium

3.  Square
trapezium
rectangle

4. Angle sum property of a
quadrilateral
 The sum of all the angles of a
quadrilateral is 360˚. This is
the angle sum property of a
quadrilateral.

5. Parallelogram
 If both pairs of opposite sides of a
quadrilateral are equal and parallel, then it is
a parallelogram.

6. Characteristics of a parallelogram
 (1)Opposite sides are equal.
 (2)Opposite angles are equal.
 (3)The diagonals of a Parallelogram bisects it
into two congruent triangles.

7. Rectangle
 It is a parallelogram with one angle=90˚.

8. Rhombus
 It is a parallelogram having all sides equal.

9. Square
 It is a rhombus where one angle is 90˚

10. kite
 It is a quadrilateral with two pairs of equal
opposite sides.

11. THEOREM
S

12.  A diagonal of a parallelogram divides it into two
congruent triangles.
 In a parallelogram opposite sides are equal.
 If each pair of opposite sides of a quadrilateral
are equal, the it is a parallelogram.
 In a parallelogram opposite sides are equal.
 If in a quadrilateral, each pair of opposite
angles is equal, the it is a quadrilateral.

13.  The diagonals of a parallelogram bisects each
other.
 If the diagonals of a quadrilateral bisect each
other, then it is a parallelogram.
 A quadrilateral is a parallelogram, If a pair of
opposite sides is equal and parallel.

14. Mid Point Theorem
 The line segment joining the midpoints of the
two sides of a triangle is parallel to the third
side.
 The line drawn through the mid point of one
side of a triangle parallel to the other side
bisects the third side.