# How to Find How Many Diagonals Are in a Polygon

To find the number of diagonals in a polygon, use the formula: n(n-3)/2 where n is the number of sides.

To **find** how many **diagonals** are in a **polygon**, first count the vertices. Next, use the formula n(n-3)/2. For example, a pentagon has 5 vertices, so the formula would be 5(5-3)/2 = 5. Therefore, a pentagon has 5 **diagonals**. This method works for any regular polygon. Remember to subtract 3 from the number of vertices before multiplying by the total number of vertices. Practice with different shapes to **determine** the number of **diagonals** in each **polygon**. This **formula** will help you **calculate** **diagonals** with ease.

Count the sides of the polygon. |

Use the formula n(n-3)/2. |

Substitute number of sides into formula. |

Multiply to get total diagonals. |

For a triangle, there are no diagonals. |

- Each vertex connects to
**n-3**other vertices. - Diagonals don’t include
**edges**of the polygon. - Diagonals are
**lines inside**the polygon. - Polygon with
**4 sides**has 2 diagonals. - For a
**pentagon**, there are 5 diagonals.

Table of Contents

- How to Determine the Number of Diagonals in a Polygon?
- What is the Formula for Calculating Diagonals in a Polygon?
- How Many Diagonals Does a Triangle Have?
- What is the Maximum Number of Diagonals in a Polygon?
- How to Find the Number of Diagonals in a Quadrilateral?
- What is the Diagonal of a Polygon with 12 Sides?
- How to Calculate the Number of Diagonals in a Hexagon?
- What is the Total Number of Diagonals in an Octagon?
- How to Find the Diagonals in a Pentagon?
- What is the Formula to Find Diagonals in an Enneagon?
- How Many Diagonals are There in a Heptagon?
- What is the Number of Diagonals in a Dodecagon?
- How to Count the Diagonals in a Nonagon?
- What is the Formula to Determine Diagonals in a Decagon?
- How Many Diagonals Does a Regular Polygon Have?

### How to Determine the Number of Diagonals in a Polygon?

To find the number of **diagonals** in a polygon, use the formula n(n-3)/2, where n represents the number of sides.

### What is the Formula for Calculating Diagonals in a Polygon?

The formula to calculate **diagonals** in a polygon is n(n-3)/2, where n is the number of sides.

### How Many Diagonals Does a Triangle Have?

A triangle has 0 **diagonals** since it does not have any internal line segments.

### What is the Maximum Number of Diagonals in a Polygon?

The maximum number of **diagonals** in a polygon can be determined using the formula n(n-3)/2.

### How to Find the Number of Diagonals in a Quadrilateral?

To find the number of **diagonals** in a quadrilateral, use the formula n(n-3)/2 with n=4.

### What is the Diagonal of a Polygon with 12 Sides?

A polygon with 12 sides would have 54 **diagonals** using the formula n(n-3)/2.

### How to Calculate the Number of Diagonals in a Hexagon?

For a hexagon, calculate the **diagonals** using the formula n(n-3)/2 with n=6.

### What is the Total Number of Diagonals in an Octagon?

An octagon has 20 **diagonals** determined by the formula n(n-3)/2 with n=8.

### How to Find the Diagonals in a Pentagon?

For a pentagon, find the **diagonals** using the formula n(n-3)/2 with n=5.

### What is the Formula to Find Diagonals in an Enneagon?

The formula to find **diagonals** in an enneagon is n(n-3)/2 with n=9.

### How Many Diagonals are There in a Heptagon?

A heptagon has 14 **diagonals** calculated using the formula n(n-3)/2 with n=7.

### What is the Number of Diagonals in a Dodecagon?

A dodecagon has 54 **diagonals** determined by the formula n(n-3)/2 with n=12.

### How to Count the Diagonals in a Nonagon?

Count the **diagonals** in a nonagon using the formula n(n-3)/2 with n=9.

### What is the Formula to Determine Diagonals in a Decagon?

Use the formula n(n-3)/2 to calculate the **diagonals** in a decagon with n=10.

### How Many Diagonals Does a Regular Polygon Have?

A regular polygon has (n-3)(n-2)/2 **diagonals** where n is the number of sides.