Attribute to the "Left Hand Path" of Tantrism, the inward approach to meditation, starting from a circle and moving towards the center.
This technique is rather involved, resulting in slight errors at the intersections (marma-sthana) and non-congruent large triangles. This method probably accounts for most of the examples in the literature.
2. On this line make nine marks at a distance of 6, 12, 17, 20, 23, 27, 30, 36, and 42 units from the top, and draw nine horizontal lines (numbered 1-9) through these marks to meet with the circle.
3. At both ends of the 1st, 2nd, 4th, 5th, 6th, 8th, and 9th lines rub off 3, 5, 16, 18, 16, 4 and 3 units respectively.
4. Join the ends of the 1st line to the centre of the 6th, the ends of the 2nd to the centre of the 9th, the ends of the 3rd to the circle at the bottom of the axis, the ends of the 4th to the centre of the 8th, the ends of the 5th to the centre of the 7th, the ends of the 6th to the centre of the 2nd, the ends of the 7th to the circle at the top of the vertical axis, the ends of the 8th to the centre of the 1st, and the ends of the 9th to the centre of the 3rd.