The doubled lune, squared like the last
Two internally tangent circles; the same construction, now doubled, needs a narrower triangle
Two internally tangent circles enclose a sector with a detached portion and an inscribed triangle above a shaded band. Leonardo notes that this case is of the same nature as the preceding one and differs in nothing except that it is 'double' where the other was 'single.' The only adjustment required is that the triangle here be made narrower.
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The same construction, doubled, with a narrower triangle
The figure d - e - a c b is said to be of the same nature as the previous one, differing only in that this one is double and the other single. Because of this doubling the triangle must be drawn narrower than before. Otherwise the method of squaring is unchanged.