Superposed triangular cards and equality of remainders
Continuing f.14v: overlapping triangles prove a Euclidean common notion
Continuing the study on the facing page (f.14v), the sheet shows several views of two triangular cards superposed, including a pair of isosceles triangles with the equal sides extended downward, combined in various ways. One caption states plainly that the two triangular cards are superposed, and another gives the common notion that if equal things are removed from equal things, the remainders will be equal. It is a demonstration of the axiom by overlapping figures.
On this page
Two triangular cards superposed
Two triangular pieces of paper are laid one over the other in repeated views, including two isosceles triangles with the equal sides prolonged, exploring how the figures coincide.
Equal removed from equal leaves equal remainders
Beside further superposed pairs the note states the common notion that if equal things are removed from equal things, the remainders will be equal.