Proportions of squares, triangles and lunes
The greatest square worth the middle one and a quarter; triangles proportional to their heights
The sheet studies proportions among plane figures. In the upper right a nest of squares is compared: the greatest square contains both the middle and the smallest, so it equals two-thirds and more, and is said to be worth the middle square and a quarter. At the left, triangles raised on a single base are shown to be in the same proportion as their heights, and several triangles carry lune-shaped figures whose values are weighed against the triangles. Squares inscribing circles and polygons inscribed in circles fill the rest of the page; further mirror-script text is present but not transcribed here.
On this page
Nested squares: the greatest worth the middle and a quarter
The greater square contains the second and the smaller, so it equals two-thirds and as much more as the smaller square. Leonardo concludes that the greater square is worth the middle one and a quarter. The figure is lettered f c g h d i.
Triangles on one base proportional to their heights
For triangles made upon the same base, the proportion from triangle to triangle is that of their heights. Four such triangles share a single base, lettered a b c d e f.
Triangles with lunes and their values
Across four figures Leonardo asks whether, if a is worth b c, the second triangle b — of the same value as triangle a — ought not also to be worth the lunes d e. The figures carry the letters c b a, e b d and g c f.
A triangle with lunes: a worth c, and b worth 2
A single triangle bearing lunes is lettered a b c, with the note that a is worth c and b is worth 2. It states the values of the parts for the comparison being drawn.