Polygonal nucleus with constant reduction of sides: form measurement equal to the radius of the circumference in which the polygon is inscribed to measurement zero.
Construction: an equilateral triangle placed with vertex downwards has two sides adjacent to two other triangles each with two sides equal to those of the equilateral triangle and one equal to half.
These two triangles each have one side adjacent to two further triangles each with two sides equal to those of the equilateral triangle and one equal to half of the short side of the two triangles preceding them.
6 bren