Name of a curve

[jenstar]

What is the technical name for the sort of curve that has bends at regular intervals like the edge of 20p and 50p coins?

[IndieSinger]

Not sure if there's a specific name for the actual bends (other than corners...) but you'd just call it the name of the shape. That is, three corners/sides = triangle, four sides = square, five sides = pentagon, six sides = hexagon, seven sides = heptagon (which is what 50p's and 20p's have), eight sides = octagon... etc.

[incitatus]

if you were to describe it mathematically you would probably call it a multicuspid. but as a general rule when you have a point of inflection on a curve it is a polynomial curve, and each point of inflection adds a term to the polynomial. so for a 7 point curve you would have a seven term polynomial.

[ChardCoins]

If it's got seven sides like the fifty pence and twenty pence, it an "Equilateral Curve Heptagon", as described at:- http://www.24carat.co.uk/fiftypencestory.html A feature of this curve is that the diameter is supposed to be constant.