Euclidean Beginnings

Dating back to the Paleolithic Period, multiple civilizations developed an instrument that makes a roaring sound for cultural and spiritual ceremonies as well as sporting events (namely bull fights). Including: Aboriginal, Scandinavian, Inupiat, and Mesopotamian groups. The one of most relevance, however, is that from Minoan civilization (2000-1500 BC), which preceded and influenced the Greeks. Their word for the spinning bull-roarer, rhomb, began to independently mean to go "round and round".

Pictured above are different types of ancient bull-roarer designs.


Euclid was a Greek scholar at the Library of Alexandria in Egypt and is credited as being the "Father of Geometry" upon publishing Elements the work of 13 books in one. In it, he uses the term rhomboid for what today is referred to as a parallelogram, as parallel lines hadn't yet be identified. The reasoning is that while neither equilateral nor right-angled, the opposite sides and angles opposite to one another are equal. In greek, ῥόμβος = rombos, now rhombus, is often defined as a quadrilateral parallelogram with all equal sides lengths and equal opposite angles.

The words Rhombus and Rhomboid sound similar, so if it's confusing, review:

• Rhomboid/Parallelogram = quadrilateral having 2 pairs of parallel opposite sides of same length


• Rombos/Rhombus = parallelogram having parallel opposite sides all of the same length



• The difference between the two is similar to that when you compare a square and rectangle.
• Some use kite as a synonym for rhombus not knowing it's not.
• Kite = nonparallelogram having 2 pairs of parallel opposite sides w/consecutive sides of the same length
  

Up Next: See how the Rhombus is used in Islamic Girih Tilings