Steiner's Chain. This is a theorem is attributed to Jacob Steiner (1796 - 1863). Given two circles [i]a[/i] and [i]b[/i], if there exist [i]n[/i] mutually tangent circles and also tangent to [i]a[/i] and [i]b[/i], then there exist infinite sets of [i]n[/i] circles satisfying this property.

To construct a Steiner's Chain with five circles.