A heptadecagon is a polygon with seventeen sides and seventeen angles. The term comes from the Greek words "hepta," meaning seven, and "deca," meaning ten, combined to indicate seventeen. Heptadecagons can be regular, where all sides and angles are equal, or irregular, where they vary in length and angle. The interior angles of a regular heptadecagon each measure approximately 158.8 degrees. The total sum of the interior angles can be calculated using the formula (n-2) \times 180 degrees, where n is the number of sides. For a heptadecagon, this results in a total of 2880 degrees.