The two circles are enough to define the sizes of the small pyramids.
The radius of the smaller circle is 110 cubits and the larger 220 cubits.
You could get even more specific and note that the primary line
a defining the placement of these pyramids is a line extending east from the southern edge of Khufu's pyramid. Then two new lines
b and
c are drawn at angles of 26.5 degrees (1:2 gradient, the same as the slopes of the Descending and Ascending Passages of Khufu's pyramid). Points are marked off on both
b and
c at distances of 110 and 220 cubits, these two distances being taken from bisecting the side of Khufu's pyramid.
Probably a new diagram is required to illustrate this.
This is enough to define the sizes of G1c and G1b. G1a is just a copy of G1b, and is placed just to the north of it.
