Right and oblique solids: parallelepiped, cube, triangle
Red-chalk geometric figures pairing upright solids with their sheared twins
Red-chalk drawings set out geometric figures: a right parallelepiped beside its oblique (sheared) twin, the same treatment for a cube, a rectangle shown with its diagonal in upright and oblique form, and a triangle. The pairs illustrate how a solid or figure may be slanted while keeping the same base — the equivalence taken up on the facing leaf. No accompanying prose is transcribed for this page.
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Right parallelepiped and its oblique twin
The lower drawings show a rectangular block (parallelepiped) and, beside it, an oblique version sheared to one side, with a cube treated the same way. The pairing demonstrates solids sharing a base and height but differing in slant.
Triangle and diagonal rectangle
At upper right a small triangle is drawn; nearby a rectangle is shown with its diagonal in upright and oblique form. These plane figures accompany the solid studies above.