Objectives

In this chapter you will: Find measures of interior and exterior

angles of polygons Solve problems involving angle measures of

polygons Identify and name polygons

Prerequisite Skills Needed

1. You’ll need to know how to solve equations

2. How to Identify a Polygon4. The Definitions of a Concave and Convex

Polygon5. The Different Types of Polygons 6. How To Name And Classify Each Polygon

A polygon is a closed figure formed by a finite number of coplanar segments such that…

1. The sides that have a common endpoint are noncollinear,and

2. Each side intersects exactly two other sides, but only at their endpoints

A regular polygon is a convex polygon with all sides congruent and all angles congruent

A convex polygon is a polygon such that no line containing a side of the polygon contains a point in the interior of the polygon. A polygon that is not convex is nonconvex or concave.

Interior Angles

Interior angles is an angle inside a shape.

Interior Angle Sum Theorem: If a convex polygon has n sides and S is the sum of the measures of its interior angles, then S= 180(n-2)

Exterior Angles The Exterior Angle is the angle between any side of a

shape, and a line extended from the next side.

The Exterior Angles of a Polygon add up to 360°

Different Types of PolygonsNumbers of sides Name of

polygon

3 Triangle

4 quadrilateral

5 pentagon

6 hexagon

7 heptagon

8 octagon

9 nonagon

10 decagon

12 dodecagon

Sources

Factmonster.com Jeopardylab.com Google.com Wikipedia.com Mathisfun.com