<Tr> <Th> Dual polygon </Th> <Td> Self </Td> </Tr> <Tr> <Th> Properties </Th> <Td> Convex, cyclic, equilateral, isogonal, isotoxal </Td> </Tr> <P> In geometry, a dodecagon or 12 - gon is any twelve - sided polygon . </P> <P> A regular dodecagon is a figure with sides of the same length and internal angles of the same size . It has twelve lines of reflective symmetry and rotational symmetry of order 12 . A regular dodecagon is represented by the Schläfli symbol (12) and can be constructed as a truncated hexagon, t (6), or a twice - truncated triangle, tt (3). The internal angle at each vertex of a regular dodecagon is 150 ° . </P>

What is the name for a 12 sided polygon