How to calculate angle of regular polygon

- How to calculate exterior angle of regular polygon
- How to calculate the size of an exterior angle of a regular polygon
- How to calculate the interior angle of a regular 9 sided polygon
- How to calculate interior angle of regular polygon
- How to calculate each interior angle of a regular polygon
- How to calculate number of sides of a regular polygon with interior angle
- Как уменьшить количество полигонов в 3d max