1. UNDERSTANDING QUADRILATERALS BY:SHIVANI, VIII
K.V A.F.S BIDAR
BANGLORE REGION
UNDERSTANDING
QUADRILATERALS
BY:SHIVANI, VIII

2. INTRODUCTION
The surface which is flat and plane is known as plane surface . For example paper .
A curve in the plane whose starting point is also the end point and which has no other self-intersections . A simple closed curve is also known as Jordan curve

3. POLYGON
Simple closed curve made up of line segments is called polygon.
CURVES THAT ARE POLYGONS Example 1
CURVES THAT ARE NOT POLYGONS
Example 2

4. CLASSIFICATION OF POLYGON
Number of sides or vertices
Classification
Sample of figure 3
Triangle 4
Quadrilateral 5
Pentagon 6
Hexagon 7
Heptagon 8
Octagon 9
Nonagon 10
Decagon

5. DIAGONALS
A diagonal is a line segment connecting two non – consecutive vertices of a polygon.

6. CONCAVE AND CONVEX POLYGON
The polygon , in which all the diagonals lie in interior is known as convex polygon.
The polygon , in which some diagonals lie in exterior is known as concave polygon.

7. ANGLE SUM PROPERTY The angle sum property of quadrilateral is 360. C B
The angle sum property of triangle is 180 .
We have divided a quadrilateral into two triangles .So, =360

8. KINDS OF QUADRILATERALS
Based on the nature of the sides or angles of a quadrilateral, it gets special names.

9. PARALLELOGRAM A quadrilateral with each pair of opposite
PROPERTIES
A quadrilateral with
each pair of opposite
side parallel.
Opposite sides are equal
Opposite angles are equal.
Diagonals bisect each other.
Adjacent angles are supplementary.

10. SQAURE All the sides are equal. All the angles are equal.
PROPERTIES
All the sides are equal.
All the angles are equal.
The diagonals bisect each other.
Also a rectangle.

11. RECTANGLE The opposite sides are equal. Diagonals are equal.
PROPERTIES
The opposite sides are equal.
Diagonals are equal.
Each of the angle is right angle.
A parallelogram with a right angle.

12. RHOMBUS of equal length. 2. All the properties of parallelogram.
1. A parallelogram with sides
of equal length.
2. All the properties of
parallelogram.
3. Diagonals are perpendicular to each other.

13. KITE PROPERTIES A A quadrilateral with exactly
two pairs of equal consec- B D
utive sides.
The diagonals are perpendic-
ular to each other C
One of the diagonal bisect the other.
In the figure m B=m D but m A= m C

14. TRAPEZIUM Trapezium is a quadrilateral with a pair of parallel sides
PROPERTIES
Trapezium is a quadrilateral with a pair of parallel sides
(NOTE: The arrow marks indicate parallel lines)

15. THE END