Geometry: subdivided triangles, pyramids and conic figures
Triangles between parallels, cones and an hourglass figure of revolution
Both leaves of this transmitted-light spread are covered with pen constructions in plane and solid geometry. On the left folio triangles are ruled with internal lines that divide them, and are set between parallels, alongside cone- and funnel-shaped bodies; the right folio repeats slender triangles, a cone enclosing a fine grid, and two triangles meeting apex to apex. No transcription accompanies this spread. Further untranscribed notes in Leonardo's hand are visible around several of the diagrams.
On this page
Triangles subdivided between parallels
The upper left of the sheet carries triangles ruled with internal lines that split them into smaller triangles and horizontal bands. Such figures treat the division of a triangle and the equality of triangles that stand on equal bases between parallel lines. No lettered labels are legible on these particular figures.
Cones and a figure of revolution
Lower on the spread appear cone- and funnel-shaped bodies, one cone enclosing a fine ruled grid, and crossed straight lines forming an hourglass-like figure of revolution. On the right folio two triangles meet point to point. Together they explore solid forms generated from triangles and circles.