POLYGON AND PLANE FIGURES

WEEK 4

POLYGON AND PLANE FIGURES

A polygon is a shape with straight sides. Triangles and quadrilaterals are polygons. Some

other polygons have special names.

Number of straight sides Name of polygon

3 Triangle

4 Quadrilateral

5 Pentagon

6 Hexagon

7 Heptagon

8 Octagon

Regular polygon

A polygon is said to be regular if all of its sides are equal. Also, all its interior angles are

equal. Consequently, all exterior angles are also equal.

Irregular polygon

If all the interior angles are not equal, then the polygon is not regular. It is then known as an

irregular polygon.

Study the table drawn below:

Name of Polygon   No of sides    No of angles.    No of triangles

Triangle.                     3                  3                     1

Quadrilateral.           …