Outer angles of a polygon

 

 OUTER ANGLES OF A POLYGON

 OBJECTIVES

1.          To understand the concept of outer angles of a polygon
2.          To understand the properties of outer angles of a polygon
3.          To understand the sum of outer angles of a polygon
4.          To solve real-life problems related to outer angles of a polygon

OUTER ANGLES

The angle between a side of a polygon and an extended adjacent side is called the outer angle or exterior angle of a polygon

Example: In the below triangle ABC, angle ACD  is  an outer angle                  

PROPERTIES OF OUTER ANGLES

1)      The outer angles at the same vertex are equal

2)      The number of outer angles of a polygon is equal to number of inner angles

3)      The inner and outer angles at each vertex form a linear pair

SUM OF ANGLES

We know that sum of inner  angles  of a polygon is (n-2)180degree.  Using the sum of inner angles we can also find the sum of outer angles of a polygon. Look at the table below. 

                      

 

POWERPOINT PRESENTATION

    

POWERPOINT PRESENTATION

SUM OF OUTER ANGLES

 

  The sum of  outer angles or exterior angles of any  polygon is 360ᵒ 

VIDEO

 

VIDEO

EXERCISE QUESTIONS

 

Answer these

 

REFERENCES

 

1.      https://www.bbc.co.uk/

2.      Class 8^th Kerala SCERT textbook

3.      Class 8^th Kerala SCERT Hand book

4.      https://www.cuemath.com/geometry/exterior-angles-of-a-polygon/