Objectives

• Classify polygons.
• Distinguish between regular and irregular polygons.
• Relate sides of polygons to the sum of the interior angles.
• Relate sides of polygons to the number of diagonals form a vertex.

Vocabulary

Polygon

A simple closed figure formed by three or more line segments.

Pentagon

five sided polygon

Hexagon

six sided polygon

Heptagon

seven sided polygon

Octagon

eight sided polygon

Nonagon

nine sided polygon

Decagon

ten sided polygon

Regular Polygon

polygon with all sides congruent

Irregular Polygon

a polygon where all of the side lengths are not congruent

Congruent

exactly the same or equal

Diagonal

a line segment in a polygon that connects nonconsecutive vertices

Nonconsecutive

not next to each other