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 the number 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 sum up to 2700 degrees, with each angle measuring approximately 158.82 degrees. Heptadecagons are of interest in geometry and can be constructed using a compass and straightedge, a topic explored by mathematicians like Carl Friedrich Gauss.