Module Overview
Polygons

A baseball stadium

Polygons are everywhere. Did you know that the outline of the playing field at the baseball stadium shown is a polygon? Would you be able to find the sum of the measures of the interior angles of this baseball playing field?

In this module, you will expand your knowledge of angle relationships. Using patterns, you will derive the formula for finding the sum of the interior angles of polygons and the sum of the exterior angles of polygons. You will also study tessellations and their relationships to patterns and polygons.

Getting Started

a honey comb Getting started iconA tessellation is a pattern made of identical polygons. A regular polygon is a polygon with sides of equal length and angles of equal measure. Figures that tessellate fit together without having any overlapping edges, or leaving any empty spaces. You can observe tessellations just about everywhere in your daily life. Have you seen the design of a honeycomb? It is a natural tessellation created by bees.

Before you begin your exploration of the angles in polygons and tessellations, see if you can find an example of a tessellation in your everyday life. Snap a photo of your example and submit it to the discussion board with an explanation of why you chose this tessellation. Then, return to the topic discussion several times over the next few days to read your coursemates’ posts. Vote for your three favorite tessellations by replying to each with the word “like” and writing at least one sentence explaining why you like it. See if your tessellation receives the most votes to become the course favorite.

Key Vocabulary

Glossary iconTo view the definitions for these key vocabulary terms, visit the course glossary.

concave polygon
convex polygon
decagon
exterior angle
heptagon
hexagon
interior angle
irregular polygon
nonagon
octagon
pentagon
point of tessellation
polygon
quadrilateral
regular polygon
tessellation
triangle