How many lines of symmetry does a regular heptadecagon have?

A regular heptadecagon, which is a 17-sided polygon, has 17 lines of symmetry. Each line of symmetry passes through one vertex and the midpoint of the opposite side or through the midpoints of two opposite sides. This symmetry arises from the equal length of all sides and equal angles of the heptadecagon. Thus, for any regular n-gon, the number of lines of symmetry is equal to n.