Two Quadrilaterals in Proportion
Two four-sided figures labelled and measured to compare their proportion
This faint pencil leaf sets two quadrilaterals side by side, marking their vertices with the letters a, d, f and b, a, c and the values 4, 12, 6 and 8. Leonardo names the relationship between the figures 'retransitive' (retransitiva), one of the proportion cases he is rehearsing after Euclid. Further faint numbers and construction lines run across the top of the sheet.
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Two quadrilaterals compared by proportion
The note lays out two four-sided figures whose sides carry the values 4, 12 and 6, 8, their corners labelled a, d, f and b, a, c. The relation between the two figures is named 'retransitive' (retransitiva), one of the proportion cases Leonardo is working through. Lightly drawn construction lines and additional figures cross the head of the leaf.