Dividing a line and turning a triangle into a parallelogram
Geometric constructions on unequal segments, with a corner list of grammatical terms
The page carries a run of elementary geometric constructions: a line divided into unequal parts, angles and triangles raised on those segments, and finally a parallelogram declared equal in area to a given triangle. Marginal notes cite proposition numbers in the manner of Euclid ('by the 26th') and observe that a triangle split on an equal base yields two halves, each half of the whole. A small word-list in the upper corner records grammatical terms ('adjectives, prerogatives, epithets'), reflecting the notebook's mix of geometry and language study. Several further triangles and lines are drawn whose captions are supplied but which bear no transcribed text.
On this page
Triangle on the smaller part of a divided line
A line is divided into unequal parts and a triangle is formed on the smaller part. The construction is justified 'by the 26th' proposition, following the citation style of Euclid's Elements.
Triangle halved on an equal base
The triangle is divided into two halves standing on an equal base, each half being one half of the whole. This states the area relation used to compare triangle and parallelogram below.
Parallelogram equal to a given triangle
On the right a parallelogram is built and declared equal to the given triangle. It is the culminating step of the sequence, transforming a triangle into an equivalent parallelogram.
List of grammatical terms
The upper left corner records a short list of grammatical terms: adjectives, prerogatives, epithets, followed by the number 441. It is a language note set among the geometry.