The document defines and discusses different types of polygons, including convex and concave polygons, and how polygons are named based on the number of sides. It provides examples of different polygons and their names for polygons with 3 to over 20 sides, and explains how to construct names for polygons with more than 20 sides using combining prefixes for Greek and Latin numbers. The document also includes objectives, definitions, comparisons of polygon types, and exercises for classifying and naming polygons.

1. POLYGONS
Prepared by:
Compuesto, Ana Liza M.
Plasquita, Sheilamae R.

2. POLYGONS
OBJECTIVES
1. I can recognize and name convex and concave
polygons.
2. I can classify polygons based on its number of
sides.
3. I can construct names of polygons based on the
given number of sides.

3. POLYGONS
Definitions:
 The word polygon is from two ancient Greek words:
poly, meaning many, and gon, meaning angles.
 It consists of three or more coplanar segments; the
segments, sides, intersect only at endpoints; each
endpoint, vertex, belongs to exactly two segments; no
two segments with a common endpoint are collinear.

4. POLYGONS
Examples:

5. POLYGONS
Polygons are named by writing their
consecutive vertices in order, such as
ABCDE or CBAED.
A polygon separates a plane into three
sets of points: the polygon itself, points
in the interior of the polygon, and points
in the exterior of the polygon.

6. POLYGONS
Compare the differences in the two polygons that follow:
C D
F H
G
G
J I
F E
None of the lines contain points FG and GH contain
in the polygon’s interior. points in the polygon’s
interior.

7. POLYGONS
A polygon is called convex if and
only if the lines containing the sides do
not contain points in the polygon’s
interior. If any of the lines do contain
interior points, the polygon is concave.
Thus, polygon CDEFG is convex, and
polygon FGHIJ is concave.

8. POLYGONS
A diagonal of a polygon is a segment that
joins two non consecutive vertices of the polygon.
Note: Polygon RSTU has two diagonals, RT and
SU.
S T
R U

9. POLYGONS
A polygon is classified by the number of its sides:
No. of sides Name of polygon No. of sides Name of polygon
3 Triangle 12 Dodecagon
4 Quadrilateral 13 Triskaidecagon
5 Pentagon 14 Tetrakaidecagon
6 Hexagon 15 Pentadecagon
7 Heptagon 16 Hexakaidecagon
8 Octagon 17 Heptadecagon
9 Nonagon 18 Octakaidecagon
10 Decagon 19 Enneadecagon
11 Undecagon 20 Icosagon

10. POLYGONS
No. of sides Name of polygon No. of sides Name of polygon
30 Triacontagon 100 Hectagon
40 Tetracontagon 1,000 Chiliagon
50 Pentacontagon 10,000 Myriagon
60 Hexacontagon 1,000,000 Megagon
70 Heptacontagon 10100 Googolgon
80 Octacontagon n n-gon
90 Enneacontagon

11. POLYGONS
For more than 20 sides, we "construct" the name by using so-called
combining prefixes:
Tens Digit Ones Digit
20 Icosa 1 Hena
30 Triaconta 2 Di
40 Tetraconta 3 Tri
50 Pentaconta 4 Tetra
60 Hexaconta 5 Penta
70 Heptaconta 6 Hexa
80 Octaconta 7 Hepta
90 Enneaconta 8 Octa
9 Ennea

12. POLYGONS
3-99 SIDES
To "construct" a name, we start with the prefix for the tens
digit, follow it by "kai" (the Greek word for "and"), then follow it
with the prefix for the units digit, and finally add "gon.“
Example: A 35-sided polygon is called a "triacontakaipentagon.“
30 and 5 gon
triaconta kai penta gon

13. POLYGONS
100-999 SIDES
For numbers from 100 to 999, we need one more combining
prefix and another rule.
To "construct" the name, we start with the prefix for the
hundreds digit taken from the "Ones Digit" table above, follow it
by "hecta," then proceed as before.
Example: A 672-sided polygon is called a "hexahectaheptacontakaidigon.“
600 70 and 2 gon
Hexa + hecta heptaconta kai di gon

14. POLYGONS
EVALUATION
Directions: Classify each figure as convex polygon, a
concave polygon, or not a polygon.
1. 2. 3.
4. 5.

15. POLYGONS
Directions: Construct a name of a polygon based on the given
sides below.
6.) 89 11.) 38
7.) 125 12.) 502
8.) 74 13.) 61
9.) 346 14.) 111
10.) 21 15.)999

16. POLYGONS
REFERENCES
Kalin Corbit.Prentice Hall, Geometry. “Polygons.” pp. 104-108
https://faculty.kutztown.edu/schaeffe/Tutorials/General/Pol
ygons.html
https://www.mathsisfun.com/geometry/polygons.html