The centre of these rays is one-third of the diameter from the top. There are altogether 13 x 6 = 78 rays which converge towards the 'heart' of the Cambridge 'angel', so she is in a sense lunar as the number 13 pertains to the Moon. There is a problem with his construction in that it doesn't well connect up to the surrounding circles. This is neat, and moreover gives us the two circle arcs in the ratio of 2:3 and the Circlemakers do like these integer ratios. The two circles overlap and form a crescent'. Now do the reverse! Construct a circle with its centre in the left corner of the small triangle and with its perimeter just touching the large triangle.

Quoting from his instructions: 'Construct a circle with it's centre in the left corner of the large triangle and with its perimeter just touching the side of the small triangle. This used two concentric triangles one four times larger than the other. I did have to admit, however, that they came out looking a bit thin by this method.Ī different version was found by Bert Janssen. I found a construction based on dividing the two circles into 6 in the usual way, here shown. The Dolphins (or 'Scimitars') appeared within two concentric circles having a 3:4 ratio.

Koch hexagon