This document discusses polygons and regular polygons. It defines a polygon as a closed geometrical figure with three or more sides. The sum of the interior angles of an n-sided polygon is (n-2)×180. For a regular polygon, where all sides and angles are equal, the outer angle is calculated by dividing the total outer angle sum of 360 degrees by the number of sides. Some examples provided include calculating the sum of angles of a 12-sided polygon as 1800, the outer angle of a 20-sided regular polygon as 18 degrees, and determining that a regular polygon with an outer angle of 60 degrees would have 6 sides.

1. LINEAR
PROGRAMMING
SUBMITTED BY
RASANATH VK
ROLL NO : 29
MATHEMATICS

2. POLYGONS

3. FRAME 1
A closed geometrical
figure having three or
more sides is called a
polygon.
Is triangle a
polygon?

4. FRAME 2
Triangle is a
polygon
Sum of angles of an
n – sided polygon is
(n – 2)×180
Find the sum of
angles of a 12
sided polygon?

5. FRAME 3
sum of angles of
12 sided polygon=
(12-2)×180=1800
Outer angle of a
polygon is an angle
got by extending any
of it’s sides outward
Draw four outer
angles of a
quadrilateral?

6. FRAME 4
The outer angle and
inner angle at a
vertex of a polygon
forms a linear pair
Find all outer
angles of an
equilateral
triangle?

7. FRAME 5
Sum of outer
angles of a
polygon is 360
What is the sum
of outer angles
of a 25 sided
polygon?
Outer angle of an equilateral
triangle = 180-60=120

8. FRAME 6
If all sides and
angles of a polygon
are equal then it is
called a regular
polygon
Sum of outer angles of a 25
sided polygon is 360
How much is
each angle of 15
sided regular
polygon?

9. FRAME 7
The outer angle of
a regular polygon is
got by dividing the
sum of outer angles
by number of sides
One angle of a 15 sided
regular polygon=
2340÷15=156
How much is
each outer angle
of a 20 sided
regular polygon?

10. FRAME 8
The number of sides
of regular polygon is
got by dividing the
sum of outer angle
by one outer angle
Outer angle of 20 sided
regular polygon=
360÷20=18
Find the number
of sides of a
regular polygon
whose outer
angle is 60?

11. FRAME 9
Number of
sides=360÷60
=6