Wondering, “How many sides does a pentagon have?” Look no further! This article will tell you everything you need to know about pentagons.
Pentagon Sides: What Makes a Pentagon
A pentagon is a type of shape called a polygon.
A polygon is a flat, enclosed shape that is made up of straight lines. To be “enclosed’ means that all sides of the polygon connect and none of the sides are curved.
There are two basic categories of polygons: regular and irregular. Regular polygons have equal sides and equal angles. Irregular polygons do not.
Pentagons can be both irregular and regular, meaning that they can have both equal sides and equal angles as well as have unequal sides and unequal angles.
How Many Sides Does a Pentagon Have?
A pentagon is any polygon that has five sides and five angles. The root of the word pentagon is “penta” which comes from the Greek word for five. “Gon” comes from the Greek word for angle. So, if you put the two words together, you get “five angles,” which corresponds to how many angles are in the shape.
As I just mentioned, in order for a shape to qualify as a pentagon, it needs to be a five sided shape and have five angles. The pentagon’s sides need to be straight: if any of them are curved, then the shape does not qualify as a pentagon.
A regular pentagon has all equal sides and angles. In a regular pentagon, its interior angles are 108 degrees and its exterior angles are 72 degrees. The angles of a pentagon add up to 540 degrees.
In an irregular pentagon, pentagon sides and angles can be different sizes.
The shape on the left is a regular pentagon. It has five sides and five angles, all of which are the same length or size.
The shape on the right is an irregular pentagon. Each side is a different length. Each angle is a different size.
Other Types of Polygons
Pentagons are a 5 sided shape. Other polygons have different amounts of sides and angles.
Here’s a list of other polygons and the number of sides they have.
| Polygon | Number of Sides |
| Triangle | 3 |
| Quadrilateral | 4 |
| Pentagon | 5 |
| Hexagon | 6 |
| Heptagon | 7 |
| Octagon | 8 |
| Nonagon | 9 |
| Decagon | 10 |
| Hendecagon | 11 |
| Dodecagon | 12 |
| Tridecagon | 13 |
| Tetradecagon | 14 |
| Pentadecagon | 15 |
| Hexadecagon | 16 |
| Heptadecagon | 17 |
| Octadecagon | 18 |
| Nonadecagon | 19 |
| Icosagon | 20 |
| Triacontagon | 30 |
| Tetracontagon | 40 |
| Pentacontagon | 50 |
Pentagon Sides: Final Thoughts
A pentagon is a type of 5 sided shape called a polygon. Polygons are flat, enclosed shapes with sides that are straight lines. How many sides does a pentagon have? A pentagon is a polygon that has five sides.
What's Next?
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