Corollary: Rhombus as a Special Case of a Parallelogram

(related to Proposition: 1.34: Opposite Sides and Opposite Angles of Parallelograms)

If two adjacent sides of a parallelogram are equal in length, then all its sides are equal in length and it is a rhombus. Fig5p5p55_2

Equivalent definitions are:

Proofs: 1

Corollaries: 1

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



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"