Proof: By Euclid
(related to Corollary: Square as a Special Case of a Rhombus)
This follows immediately from Prop. 1.46, and the definitions of a square and a rhombus.
Adapted from CC BY-SA 3.0 Sources:
- Callahan, Daniel: "Euclid’s 'Elements' Redux" 2014
Adapted from (Public Domain)
- Casey, John: "The First Six Books of the Elements of Euclid"