 |
| Introduction |
|
|
| A plane figure bounded by straight lines is called a rectilinear figure. |
| |
|
| |
| A closed rectilinear figure having three or more sides is called a polygon. |
| |
|
| |
| Concave Polygon |
| |
| If at least one angle of a polygon is greater than 180o, then it is called a concave polygon. |
| |
 |
| |
| Interior ÐDCB is greater than 180o. |
| |
 |
| |
| Convex Polygon |
| |
| If every angle of a polygon is less than 180o, then it is called a convex polygon. |
| |
 |
| |
| Regular Polygon |
| |
| It has all the angles and all the sides equal. In the figure,
ÐA = ÐB =
ÐC = ÐD =
ÐE, and AB = BC = CD = DE = EA. |
| |
 |
| |
| Name of Polygons with reference to the number of sides: |
| |
 |
| |
 |
| |
| Triangles and quadrilaterals are also polygons with three sides and four sides respectively. |
| |
| A diagonal of a polygon is a line joining any two non-adjacent vertices. |
| |
