Changes

# http://www.mathopenref.com/quadrilateral.html : Simple explanation about quadrilaterals.

# http://www.mathopenref.com/quadrilateral.html : Simple explanation about quadrilaterals.

# http://www.slideshare.net/muzzu1999/types-of-quadrilaterals-and-its-properties-group-4  : This website has a very good activity on properties of quadrilaterals.

# http://www.slideshare.net/muzzu1999/types-of-quadrilaterals-and-its-properties-group-4  : This website has a very good activity on properties of quadrilaterals.

# http://www.cimt.plymouth.ac.uk/projects/mepres/book8/bk8i1/bk8_1i3.htm    This is a very good website for students to understand classification of quadrilaterals as per their properties. The activity is given in the form of a flow chart.

# http://www.cimt.plymouth.ac.uk/projects/mepres/book8/bk8i1/bk8_1i3.htm    This is a very good website for students to understand classification of quadrilaterals as per their properties.

==Reference Books==

==Reference Books==