Dodecahedron, Solids, and Turning a Cube into a Pyramid
Lettered solids and a rule for building, from a cube, a pyramid proportional to a given one
The upper part of the sheet carries a lettered dodecahedron drawn with radiating internal lines, along with a row of solids: a pyramid, a wedge, a pentagonal-based pyramid split into five triangles, a triangular-based pyramid, and a wedge. A further note, keyed to a cube a and a square-based pyramid b, begins the problem of transforming a cube into a pyramid proportioned in itself to a given pyramid. The demonstration breaks off at "You will therefore make...".
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Lettered dodecahedron
A twelve-faced solid is drawn with internal lines radiating to its center and lettered around its faces: a e d, b c, o r e g, p h, m n i, and a b c d e. The labels mark the vertices and faces used in the decomposition of the body.
A row of pyramids and wedges
The sheet shows in sequence a pyramid, a wedge, a pyramid with a pentagonal base divided into five triangles, a pyramid with a triangular base, and a wedge. These are the elementary solids into which the larger bodies are resolved.
Transforming a cube into a proportional pyramid
The note sets the problem of making, from a cube, a pyramid proportioned in itself according to the proportion of a given pyramid. Let a be the proposed cube and b the given pyramid into which it is to be transformed. The construction begins but is left unfinished.