What is a polygon? a closed figure made by joining line segments Each line segment intersects exactly two others. line segments do not intersect *All images are either original artwork or are used with permission from Microsoft Word and Microsoft Online Design Gallery.

Are these figures polygons? yes no yes no

What is a regular polygon? A regular polygon is a polygon whose sides are all the same length and whose angles are all the same.

These are not examples of regular polygons. The sides are not all the same length. The angles are not all the same.

Let’s look at some different kinds of polygons. triangle What is a three-sided polygon?

Polygons parallelogram What is a four-sided figure whose opposite sides are parallel?

Polygons rectangle What is a four-sided polygon whose sides and angles are all the same?

Polygons square What is a parallelogram or rectangle with four equal sides and angles?

Polygons rhombus What is a parallelogram whose sides are all the same length?

Polygons trapezoid What is a four-sided polygon having exactly one pair of parallel lines?

Polygons pentagon What is a five-sided polygon?

Polygons hexagon What is a six-sided pentagon?

Polygons heptagon What is a seven-sided pentagon?

Polygons octagon What is an eight-sided pentagon?

Let’s review the polygons we‘ve learned about today. regular polygon triangle parallelogram rectangle square rhombus trapezoid pentagon hexagon heptagon octagon

Can you identify these polygons?

Match these. Triangle eight sides Heptagon three sides Octagon seven sides

Match some more. Pentagon four sides Hexagon five sides Square six sides

Using your geoboards or dot paper, replicate these polygons.                    