Polygon Sorting Activity

Students will already be familiar with many, many shapes, but they may not know the mathematical names. One simple way to start is to identify whether or not a shape is a polygon. A polygon is closed figure made up of at least three sides and angles. Triangles, quadrilaterals, pentagons, hexagons, etc. are all polygons. Polygons can be weird shapes, have convex and concave sides, and can have any number of sides. Any shape with curves or open ends is NOT a polygon.

In this activity, students will move shapes from a template into the appropriate columns on their own storyboard. Interactive whiteboards or projected computer screens make this an engaging class activity, but students can just as easily work individually or in pairs on a computer.

See also Polygonia and Roundsville for a short math story.

Polygons can be categorized by the number of sides (and therefore angles) they have:

• Three-sided polygons - triangles
• Four-sided polygons - quadrilaterals
• Five-sided polygons - pentagons
• Six-sided polygons - hexagons
• Seven-sided polygons - heptagons*
• Eight-sided polygons - octagons
• Nine-sided polygons - nonagons*
• Ten-sided polygons - decagons*
• Eleven-sided polygons - hendecagons*
• Twelve-sided polygons - dodecagons*

*These shapes are not required by the Common Core, but it is nice to have the names handy if inquiring minds want to know.

Student Instructions

Sort the shapes provided into either Polygon or Not a Polygon.

1. Click "Start Assignment".
2. Look at the shapes in the first column. Examine their properties and what they look like.
3. Drag all the polygons into the cell labeled "Polygon".
4. Drag all the non-polygons into the cell labeled "Not a Polygon".