# Diagonal of a Polygon

## Diagonal of a Polygon

Line segment that joins two nonconsecutive vertices of a polygon.

### Example

Segments AC and AD are diagonals of the pentagon ABCDE.

### Properties

• A triangle does not have a diagonal.
• To calculate the number $$N$$ of diagonals of a polygon with n sommets, vertices, you can use the formula:  $$N=\dfrac{n(n\space –\space 3)}{2}$$.