Introduction of Polygons and its angles

1. Polygons
Submitted by
Jenifa.J.L
3rd semester B.Ed
Mathematics
Govt college of Teacher
Education Thycaud,
Thiruvananthapuram, Kerala

2. Polygons
A polygon is a closed figure made-up of straight line
segments in a two dimensional plane. Polygon is
combination of two Greek words, i.e. Poly means
many and gon means sides. A minimum of three
line segments is required to connect end to end, to
make a closed figure.

3. Examples of polygons

4. Examples of non polygons

5. Shapes Number
of sides
Name of
Polygons
3
Triangle
4 Quadrilateral
5 Pentagon
6 Hexagon

6. What do we call a 16 sided polygon?
16- gon

7. Apolygonwithn sidesis
called an n-gon.

8. Sum of interior angles
Number of sides
Number of
triangles Sum of angles
3
1×180° = 180°
4 2 2×180° = 360°
5 3 3×180° = 540°
6 4 4×180° = 720°
.
n
.
(n-2)
.
(n-2)×180°
1

9. Thesumoftheinterioranglesofan
n-sidedpolygonis(n-2)×180°.
Sum of interior angles

10. Sum of exterior angles
Sum of interior
angles
Each interior angle
of regular polygon
Sum of exterior
angles
Triangle 180° 60° 360°
Quadrilateral 360°
90° 360°
Pentagon 540° B 108° 360°
Hexagon 720° 120 360°
B. .
(n-2)×180°
.
(n-2)×180° 360°

11. Sum of exterior angles
The sum of the exterior angles
of any polygon is 360°.

12. Thank you