Geometric Figures for Perspective and Foreshortening
Squares with inscribed triangles tilted forward to study foreshortened reductions
The folio is a set of geometric constructions studying how upright figures foreshorten when tilted toward the ground. Squares carry inscribed isosceles triangles and horizontal dividers; in several the triangle is shown tilted forward or inverted, with sight-lines drawn from base vertices to points such as m, v and o on an upper parallel. The sheet is almost wordless, only diagram letters (m n; v x, n m, S t; c f, r t, o n) accompanying the drawings, with faint pencil repetitions of the same figures at the right.
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Square with inscribed isosceles triangle, vertex n
A square, its top and bottom extended by parallels, holds an inscribed isosceles triangle with vertex n and a horizontal divider below mid-height. A sight-line rises from a lower vertex to cross the upper parallel at m, marking how the divided figure reads once projected.
The triangle tilted forward from the square (vertex x)
The same figure is shown tilted forward: the triangle shares the square's base S t but its vertex x lands on the upper parallel outside the square, as though it had fallen forward. The divider n m and a sight-line from t up to v record the foreshortened position against the upright figure.
