Type B Flat Circle

The below pictures and instructions will provide a clue of how these Megaliths were built.  This is of course, the Type B Flat Circle plan.  Remember that Professor Thom found that he could use the Megalithical Yard to construct these plans.  It is suggested that you take a look at how the Type A Flat Circle is constructed before going any further.

From the construction of the Type A flat circle, the properties are as follows.
The horizontal line is the diameter of the red semi-circle.  The two black lines (making a V) meets from the lower quadrant of the red arc, to the midpoints of the two blue lines respectively.  The two blue lines form a 30 degree angle with the horizontal line.

Extend lines EC and ED such that the portions of the lines beginning from F and G respectively are equal to FA and GB respectively.

Hence, the lines FA and GB creates the two red arcs from the fact that they are their radii.  Also, The two lines forming the 'V' are the radii of the green arc.