Proposition: 1.35: Parallelograms On the Same Base and On the Same Parallels

Euclid's Formulation

Parallelograms which are on the same base and between the same parallels are equal1 to one another.

fig35e

Modern Formulation

Parallelograms on the same base (\(\overline{BC}\)) and between the same parallels (\(\overline{AF}\), \(\overline{BC}\)) are equal in area.

Proofs: 1

Proofs: 1 2 3


Thank you to the contributors under CC BY-SA 4.0!

Github:
bookofproofs
non-Github:
@Calahan
@Casey
@Fitzpatrick


References

Adapted from CC BY-SA 3.0 Sources:

  1. Callahan, Daniel: "Euclid’s 'Elements' Redux" 2014

Adapted from (Public Domain)

  1. Casey, John: "The First Six Books of the Elements of Euclid"

Adapted from (subject to copyright, with kind permission)

  1. Fitzpatrick, Richard: Euclid's "Elements of Geometry"

Footnotes


  1. Here, for the first time, "equal" means "equal in area", rather than "congruent" (translator's note).