Triangles and a segment: a proof of proportionality
Two triangles a-b-c and d-e-f, a segment o-g, and three smaller triangles
In faint pencil the sheet sets out a demonstration of proportionality. Two large triangles lettered a-b-c and d-e-f stand at the top, a short segment marked o and g lies between them, and a row of three small triangles sits below. Leonardo captions the arrangement a diagram for proving proportionality; a pencil page-number (171) is in the corner.
On this page
Two triangles lettered a-b-c and d-e-f
Two large triangles are labelled at their vertices, one a - b c and the other d - e f. They form the principal figures of the demonstration.
A segment marked o and g
A short straight segment lettered o and g is drawn among the triangles, supplying a reference line for the proof.
Diagram to demonstrate proportionality
Three small triangles, each marked a, accompany the larger figures. Leonardo labels the whole a scheme for demonstrating proportionality among the parts.