If your child is starting geometry, they have probably been introduced to a lot of cool shapes like triangles, circles, and rectangles. Another important shape for your child to learn about is the pentagon, which is a polygon with 5 sides. To learn more about pentagons and their properties, scroll to the bottom of the page or check out some of our resources.
Learn More About Pentagons
Pentagons can be a lot of fun to work with, but how will your child be able to recognize which shapes are pentagons? We’ve put together some properties of a pentagon below so that you can help your child familiarize themselves with this cool 5 sided shape.
A regular pentagon has:
- 5 straight sides that form a closed shape
- Interior angles of 108 degrees and exterior angles of 72 degrees
- Area of approximately 1.72 × s2, where s is the length of a side
Your child will most likely see regular pentagons when working with shapes, but there is a chance that they will also encounter some irregular pentagons. Irregular pentagons are pentagons that do not have all the properties that a regular pentagon is supposed to have. Two types of irregular pentagons are the concave pentagon and the convex pentagon:
- Concave Pentagon: Any pentagon with at least one internal angle greater than 180 degrees
- Convex Pentagon: Any pentagon with no internal angles greater than 180 degrees
With our pentagon property cheat sheet, your child will be a master at working with and recognizing pentagons! After they have explored the different exercises on this page, step over to our hexagons page
to make things a little more challenging with this 6-sided shape.