4. A closed plane figure bounded by three or more
straight sides that meet in pairs in the same number
of vertices, and do not intersect other than at these
vertices.
Comes from Greek word “poly” means many and
“gon” means angles.
Polygon
5. A union of non-collinear segments, the sides, on a plane
that meet at their end points, the vertices, so that the
endpoint is contained by exactly two segments.
Polygon
6. Parts of a Polygon
o The side of the polygon is called as the surface of
polygon.
o The vertex of a polygon is the connection between
two sides.
o The diagonal is known as a line that connects two
points in the boundary of a polygon through the
centre.
7. o The interior angle is the angle that is
formed inside the polygon by two
adjacent sides.
o The exterior angle is the angle formed by
two adjacent sides, outside the polygon
by extending one of the sides of the
polygon.
Parts of a Polygon
8. Classification of a Polygon
Convex Polygon- if lines containing the sides of the polygon
do not cross the interior of the polygon.
Concave Polygon- if there are two points somewhere inside it for
which a segment with these as its endpoints cuts at least 2 of the
sides of the polygon
10. Type of Polygons
Equilateral Polygon- all sides are equal.
Equiangular Polygon- all angles are equal.
Regular Polygon- both equilateral and equiangular.
11. Activity
Recall:
1)A polygon is________________________________.
2)A polygon is equilateral if _____________________.
3)A polygon is equiangular if ____________________.
4)A polygon is regular if________________________.
Determine:
1)Polygon having 8 sides. ______________________
2)Polygon having 12 sides. _____________________
3)Polygon having 11 sides. _____________________
4)Polygon having 5 sides. ______________________
