I have to remove the 6 greatest portions of the circle, or their value, and the remainder stays squarable.
* Similar parts hold the same proportion among themselves, with the similar parts, as their similar wholes hold.

* Similar parts hold the same proportion among themselves as their similar wholes hold among themselves.

I shall make of 6 seven equal parts, and beyond this whatever number I wish.

Worth 12.

Worth 12.

I shall make these 6 stars of biangles; you diminish the sixth of them.

containing four circles.
This shows the proportion that the greatest circle has with the smallest circle.

* To grow from 36 to 42 biangles takes 6 biangles, that is a star of 6 biangles. Therefore it grows by 6 biangles, which complete the number of 42 biangles, and these have to remain of the value of the said 36 biangles. And to do this it is necessary that such biangles diminish in figure, and this diminution the 36 biangles acquire, from which one draws from 36 to 42 biangles; and so the value of the 36 biangles serves for 42 biangles equal among themselves. And so from 36 you will remove the sixth, which is 6 biangles, that is the value of those 6 biangles.

* Similar parts hold the same proportion among themselves as their similar wholes. Similar parts hold the same proportion among themselves, etc. I shall square the 7 as shown by the penultimate [proposition] of the first [book] of Euclid, which will be g f, and so I shall have made the two circles a f, in which I shall make the two curvilinear stars, whose proportion among themselves is as that of their circles and of their squares; and this conception concludes it.
Therefore the 6 stars of the 6 equal squares a b hold within them 36 biangles and 72 least portions, twelve of which go against one of the greatest portions; and the proportionality from the least to the greatest circle is twelvefold, and so the whole is accorded with its parts, as the conception stated above teaches us. There follows the second part e d, which makes 7 squares from the 6 written above, which 7 are worth the 6 above. The same happens with the 7 circles and the 42 biangles and the 84 portions, which are worth the 72 portions said before, and each of its 6 portions is worth 42 biangles.

* Now if of the 6 stars of biangles you diminish the sixth, which sixth you add to 36, you make the sum of 42 biangles; and this diminution diminishes the quality and not the quantity of that 36, that is, the number of 36 biangles stays fixed; but their figure diminishes the sixth of its quantity, so that in diminishing 36 sixths of biangles they make 6 whole biangles. These 6 biangles, added to 36, make 42 biangles; but because those 36 biangles remain five sixths of their first size, and the 6 sixths that you added to the 36 sixths are for each 6 sixths, this shows the biangles to be greater by 1/6 than each of the other 36 sixths.