2. POLYGONS
• A POLYGON is a closed figure made up of three or more line segments.
‘Poly’ means many, hence, polygon means a ‘many sided figure’. Some
examples of polygon are:
Some examples of none polygons are:
3. Some polygons have special names that correspond to
the number of sides in the polygon
SIDES NAME FIGURE
3 TRIANGLE
4 QUADRILATERAL
5 PENTAGON
6 HEXAGON
7 HEPTAGON
8 OCTAGON
9 NONAGON
10 DECAGON
11 HENDECAGON
12 DODECAGON
4. TYPES OF POLYGONS
1. CONVEX POLYGON: in a polygon, if the line joining
any two points lies inside the polygon, then the
polygon is a convex polygon.
2. CONCAVE POLYGON: In a polygon, if there exists
even one line, which when joining two points of a
polygon, does not lie inside the polygon, then the
polygon is a concave polygon.
5. 3. REGULAR POLYGON: A polygon in which all
the sides and all the angles are equal is
known as regular polygon.
6. 4. IRREGULAR POLYGON: The polygons that are
not regular are called irregular polygons.
8. Properties parallelogram rectangle rhombus square
Sides: opposite sides are equal
adjacent sides are equal
opposite sides are parallel
Angles: opposite angles are equal
adjacent angles are equal
all angles are right angles
Diagonals: diagonals are equal
diagonals bisect each other
diagonals bisect each other
at right angles