5. A quadrilateral is a four sided polygon.
There are several types quadrilateral such as rectangle,
square, parallelogram, rhombus etc.
The sum of the angle of a quadrilateral is 360 degree.
6. A pentagon is a five sided polygon.
The sum of the angles of a pentagon is 540 degree.
7. A hexagon is a six sided polygon.
The sum of the angles of a hexagon is 720 degree.
8. A heptagon is a seven sided polygon.
The sum of the angles of a heptagon is 900 degree.
9. An octagon is an eight sided polygon.
The sum of the angles of an octagon is 1080 degree.
10. A nonagon is a nine sided polygon.
The sum of the angles of a nonagon is 1260 degree.
11. A decagon is a ten sided polygon .
The sum of the angles of a decagon is 1440 degree.
12. A polygon with equal sides and equal angles.
Example :- Equilateral triangles, square,
regular pentagon etc.
13. In an irregular polygon, one or more sides do not
equal to the length of the others.