1. 10.1 Naming Polygons

2. Vocabulary What You'll Learn
Naming Polygons
What You'll Learn
You will learn to name polygons according to the number of
_____ and ______.
sides
angles
Vocabulary
1) regular polygon
2) convex
3) concave

3. A polygon is named by the number of its _____ or ______. sides angles
Naming Polygons
A polygon is a _____________ in a plane formed by segments, called sides.
closed figure
A polygon is named by the number of its _____ or ______.
sides
angles
A triangle is a polygon with three sides. The prefix ___ means three.
tri

4. Prefixes are also used to name other polygons. Prefix Number of Sides
Naming Polygons
Prefixes are also used to name other polygons.
Prefix
Number of
Sides
Name of
Polygon
tri- 3
triangle
quadri- 4
quadrilateral
penta- 5
pentagon
hexa- 6
hexagon
hepta- 7
heptagon
octa- 8
octagon
nona- 9
nonagon
deca- 10
decagon

5. Terms Naming Polygons A vertex is the point of intersection of
two sides.
Consecutive vertices are
the two endpoints of any
side. U T S Q R P
A segment whose
endpoints are
nonconsecutive
vertices is a
diagonal.
Sides that share a vertex
are called consecutive
sides.

6. An equilateral polygon has all _____ congruent. sides
Naming Polygons
An equilateral polygon has all _____ congruent.
sides
An equiangular polygon has all ______ congruent.
angles
A regular polygon is both ___________ and ___________.
equilateral
equiangular
equilateral
but not
equiangular
equiangular
but not
equilateral
regular,
both equilateral
and equiangular
Investigation: As the number of sides of a series of regular polygons increases, what do you
notice about the shape of the polygons?

7. A polygon can also be classified as convex or concave.
Naming Polygons
A polygon can also be classified as convex or concave.
If all of the diagonals
lie in the interior of
the figure, then the
polygon is ______.
If any part of a diagonal lies
outside of the figure, then the
polygon is _______.
concave
convex

8. Naming Polygons
End of Section 10.1