3.1    INTRODUCTION

 Polygon  is a combination of two Greek words  Polus  +  Gonia, in which Polus means many and Gonia means corner or angle.

Plane Surface:  A flat surface like paper is a plane surface.

Plane Curve:  When we get a curve by joining the number of points without lifting the pencil it is a plane curve.

It could be an open or closed curve.