This document defines and describes different types of quadrilaterals. It begins by defining a quadrilateral as a figure with four sides and four angles. It then defines key terms like adjacent sides. The main types of quadrilaterals discussed are trapezium, kite, rhombus, square, parallelogram, and rectangle. Each shape is defined, such as a rectangle having four right angles and parallel opposite sides. Properties of different quadrilaterals are also covered, like diagonals bisecting each other in a rhombus. In the end, it states the angle sum property that the interior angles of any quadrilateral sum to 360 degrees.

2. Quadrilateral – The word ‘quad’ means four and the word ‘lateral’ means
sides.
- It is a figure bounded by four line segments such that
no three of them are parallel to each other
- It has four sides, vertices, and angles
SOME IMPORTANT DEFINITIONS:-
a) Adjacent sides- also known as consecutive sides
- two sides of quadrilateral with common vertex
b) Opposite sides- two sides of quadrilateral with no common end- point
c) Adjacent angles- also known as consecutive angles
- two angles of a quadrilateral with common arm
d) Opposite angles- two angles of a quadrilateral with no common arm

3. Trapezium Kite
Rhombus Square
Parallelogram Rectangle
Types of Quadrilaterals

4. Let us discuss about various kinds of quadrilaterals briefly:-
TRAPEZIUM A quadrilateral with one pair of parallel sides
ISOSCELES TRAPEZIUM  A trapezium with non parallel sides as equal
TRAPEZIUM ISOSCELES TRAPEZIUM

5. PARALLELOGRAM  A quadrilateral with both pairs of opposite sides equal
RHOMBUS  A parallelogram with all sides equal

6. RECTANGLE  A parallelogram whose each angle is right angle
SQUARE  A rectangle with pair of adjacent sides equal

7. KITE  A quadrilateral with two pairs of equal adjacent sides and unequal
opposite sides

8. Let us discuss about various types of quadrilaterals in detail !!!
*RECTANGLE  opposite sides are parallel and equal
 all angles are right angles
 diagonals are equal
 diagonals bisect each other
*SQUARE  all sides are equal
 all angles are right angles
 opposite sides are parallel
 diagonals are equal
 diagonals bisect each other at right angles
 diagonals are perpendicular to each other
*RHOMBUS  opposite sides are parallel
 all sides are equal
 opposite angles are equal
 diagonals bisect each other
 diagonals are perpendicular to each other

9. *KITE two pairs of equal adjacent sides
*PARALLELOGRAM  opposite sides are equal
 opposite angles are equal
 diagonals bisect each other
 diagonals divide it into two congruent triangles
 bisect of any two consecutive angles intersect at right
angle
 its angle bisectors form a rectangle
*TRAPEZIUM  one pair of opposite sides are parallel
(Isosceles Trapezium has non- parallel sides equal to each other)

10. ANGLE SAUM PROPERTY OF A QUADRILATERAL
This property states that sum of four angles of a quadrilateral is 360

11. SUBJECT – Maths
CLASS – IX
CHAPTER – Quadrilaterals
GROUP MEMBERS – Ankita, Jeetin, Kamlesh, Shikha, Radhika, Surbhi,
Zenul
SUBMITTED ON – 22.11.2013
GROUP ACTIVITY OF CLASS IX