Reflection angles at a circle, with geometric constructions
A perpendicular curving toward a shorter line; equal incident and reflected angles
The transcribed note states that a straight perpendicular raised on the line n m bends toward the line c s the more, the shorter c s is than the line h m, and that the angles of incidence formed between a circle and the incident and reflected line are equal to one another outside the circumference, while the angles generated within it are likewise equal, closing with 'it is proved.' The sheet is dominated by geometric constructions: a cone on a curved (conic) base, a circle inscribing intersecting triangles and a hexagram, and a large circle met by tangent lines from an external point. A small labelled triangle sits beside the note in the left margin, and the upper corners carry arithmetic jottings and a shaded looped sketch that the transcription does not cover.
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A perpendicular curving toward a shorter line
The straight perpendicular raised upon the line n m bends toward the line c s, and its curvature grows the greater the shorter c s is than the line h m. The note stands beside a small labelled triangle in the left margin.
Equal angles of incidence and reflection at a circle
The angles of incidence formed between the circle and the incident and reflected line are equal to one another outside the circumferential line, and the angles generated within that circumference are likewise equal. Leonardo closes the demonstration with the word 'proved.'
Conic and inscribed-polygon constructions
The centre and lower part of the sheet are filled with geometric figures: a cone standing on a curved (conic) base, a circle inscribing intersecting triangles and a hexagram, and a large circle met by tangent lines drawn from an external point. The transcription leaves these figures unlettered.