Types of Polygons
After learning what a polygon is, the next step is understanding the different types of polygons. While all polygons are closed shapes with straight sides, they can look very different depending on how many sides they have.
In this post, we’ll explore common types of polygons students learn in 3rd and 4th grade and how to identify them.
Also, I will share an excellent reference tool to help your students with identifying quadrilaterals.
What Do All Polygons Have in Common?
All polygons:
- Are closed shapes
- Have straight sides
- Have three or more sides
Polygons are named based on the number of sides they have.
Triangle
A triangle is a polygon with three sides and three vertices.
Triangles are one of the simplest polygons and are often the first type students learn.
Quadrilateral
A quadrilateral is a polygon with four sides and four vertices.
Examples include squares, rectangles, rhombuses, parallelograms, and trapezoids.
Pentagon
A pentagon is a polygon with five sides.
Students often recognize pentagons from shapes like house outlines or classroom signs.
Hexagon
A hexagon is a polygon with six sides.
A common real-life example of a hexagon is a honeycomb.
Heptagon and Octagon
A heptagon has seven sides, and an octagon has eight sides.
Stop signs are a great real-world example of an octagon.
Step-by-Step: How to Identify a Polygon
Students can use these steps to identify the type of polygon:
- Step 1: Check that the shape is closed.
- Step 2: Make sure all sides are straight.
- Step 3: Count the number of sides.
The number of sides tells the name of the polygon.
Common Student Mistakes
Students may:
- Forget to count sides carefully
- Confuse curved shapes with polygons
- Mix up polygon names
Using visuals and counting sides helps students avoid these mistakes.