...although, strictly speaking, a 50p piece is not really a polygon as a polygon is a plane figure that is bounded by a finite chain of straight line segments closing in a loop to form a closed chain or circuit.
Not only is a 50p piece a 3d shape, but also the 2d face has 7 curved sides making it an equilateral curve heptagon which is not a polygon.
I was just referring to another post where I was being 'nerdy' by pointing out that a little poem was not, in fact, a Haiku.
Don't worry about it, ff. It's just my sense of humour.