 Hello and welcome to this session. In this session we will discuss about polygons, a closed plain figure bounded by lines of polygons. Polygons are so called many sided figures since this word poly means many. Now we will discuss the types of polygons, a convex polygon joining an 80 degrees. This figure A, B, C, D, E, F is a convex polygon. When we join the vertices A and B of this polygon then the line segment A, B lies completely inside this polygon A, B, C, D, E, F. If we join any two vertices of the polygon, the line segment joining the two vertices lies completely inside this polygon of the convex polygon. Also each interior angle is less than 180 degrees, at least an 80 degrees. C, D, E, F is C and E of the polygon. Reflects are there, that is it is of measure more than 180 degrees. Polygons are also classified into the number of sides. We have joined the vertices A, C, A, D and A, E.