As per geometry, a closed figure with 3 or more sides and vertices can be termed a polygon. While a three-sided polygon is called a triangle, and a 4-sided polygon is called a quadrilateral. How many sides does a pentagon have? There can still be doubts about the sides of a pentagon which would be answered in this article. Read on to know more.

**1. How many Sides does a Pentagon have?**

The answer to this question would be **five**. The first part of the word pentagon is pent, which means five, and gon is the suffix used to describe a polygon. Gon comes from the Greek word gonia meaning angular or angled. So, a pentagon is a polygon with 5 sides. (See How Long is 1 Billion Seconds in Hours?)

**2. How many Angles does a Pentagon have?**

Pentagon is the name given to a polygon having **five angles**. There are five internal angles as well as five external angles. A combination of an internal angle and its adjacent external angle sums up to **180°**.

**3. What are Pentagon Properties?**

As you have learned, a pentagon is a polygon with 5 sides, 5 vertices, and 5 internal angles. Now, let’s discuss the properties of a pentagon as listed below:

- In the case of a pentagon, the sum of all the interior angles will always sum up to
**540°**. - There are two types of pentagons based on the equality of their sides and angles which are
**regular and irregular**. - If all five pentagon sides are equal in length, it is a regular pentagon. Otherwise, it is an irregular pentagon.
- A regular pentagon can be either
**convex or concave**, depending on if the vertices are pointing outwards or inwards. - If all the vertices are pointing outwards, it is convex. If any of the vertices is pointing inward, the pentagon is concave.
- In the case of a regular pentagon, each interior angle will measure
**108°**and each exterior angle**72°**. - The sum of all the exterior angles always sums up to
**360°**. (See What Kind of Information do you need?)

**4. Do all Pentagons have 5 Sides?**

Always five! There is no alternative answer to the question: how many sides does a pentagon have? Pentagons are meant to have **5 sides and 5 angles**, hence the name pentagon.

**5. Are All Sides of a Pentagon the Same Length?**

Pentagons come in two types: regular and irregular. In an irregular pentagon, the sides of the pentagon are not the same. Even if only one side does not match the other four, it becomes an irregular polygon. Only in the case of a **regular pentagon, all the sides of a pentagon are of the same length.** Such a pentagon can be called an **equilateral one** if the angles are of the same measure. (See What is 5 Feet 6 Inches?)

**6. How many Sides does a Triangle have?**

Words like trimester, tripod, and triplets always stand for something which is three in number. Similarly, the triangle suggests the closed figure formed would have **3 angles**. The figure should have **3 sides and 3 vertices** to enclose three angles. This is why a 3-sided enclosed figure is named a triangle. Also, check out what is a Circle Degree Chart?

**7. How many Sides does a Square have?**

A square is a quadrilateral where each interior angle is a right angle, and all the sides are equal in length. A quadrilateral is an enclosed figure or a polygon with **4 sides and 4 angles**. Therefore, a square has 4 sides and 4 angles inside its vertices. (See How many cm in a Meter?)

**8. How many Sides does a Quadrilateral have?**

Quad is a prefix used to describe something 4 in number. So, a quadrilateral **has 4 sides and 4 angles**. Examples of quadrilaterals are **squares, rectangles, and parallelograms**. We can see many things in the shape of a quadrilateral: rugs, mats, sheets of paper, bedsheets, etc. (See What does the Diamond Shaped Traffic Sign Mean?)

**9. How many Sides does a Hexagon have?**

Besides, how many sides does a pentagon have, do you know about a hexagon? A hexagon is a name given to a polygon that has **6 sides and 6 angles**. Hex is the prefix used to denote anything 6 in number. So, according to this theory, a hexagon is meant to have 6 sides.

**10. How many Sides does a Heptagon have?**

Hepta or septa is a prefix used to denote anything seven in number. For an enclosed figure like a polygon, a heptagon or septagon is the one that has **7 sides and 7 angles**. Seven angels are present on both sides each internal and external. (See What is Three Eighths as a Decimal?)

**11. How many Sides does an Octagon have?**

Octa is the prefix used to name something that is 8 in number. According to this theory, the octagon is the name given to a polygon having **8 sides, 8 vertices, and 8 angles**. There would be 8 angles on each side, interior, and exterior. The octagon shape is used commonly in traffic signs as the stop sign above. Octagons also come in types which are **regular and irregular**.

**12. What Polygon has 9 Sides?**

As you are aware of how many sides does a pentagon have, you must know that Polygons can have numerous sides and be named separately per the number of sides. A polygon that has nine sides is called a **nonagon**. Nine is denoted by the prefix **nona**. (See How many Miles is 5k?)

**13. What is a 10 Sided Polygon?**

A polygon having 10 sides, 10 vertices, and 10 angles is called a **decagon**. **Deca** is the prefix to denote anything 10 in number. We call 10 years a decade due to the same reason.

**14. What type of Polygon has 12 Sides?**

Apart from knowing how many sides does a pentagon have, note that a polygon with 12 sides, 12 angles, and 12 vertices is called a **dodecagon**. Dodecagons can be of different types depending upon the measure of their sides, angles, and other such properties. A **regular dodecagon** has all 12 sides equal in length and all the interior and exterior angles of equal measures. In the case of an **irregular dodecagon**, at least one side or angle would be of a different measure than the rest. (See What is the Correct Order of Steps in the Scientific Method?)

Apart from the shapes mentioned above, polygons can have numerous types and properties. The names of polygons are based on the number of sides it has**. Polygons are named n-gon**, where n is the prefix denoting the number of sides. A polygon has to have edges and vertices. A closed figure with a curved surface cannot be defined as a polygon. So, what is a pentagon, and how many sides does a pentagon have? These questions have been answered using the polygon definition. (Also read What is Critical Thinking?)