Home Geometry Euclid's Elements         By Antonio Gutierrez
Euclid's Elements Book I, Proposition 9: To bisect a rectilinear angle.
Level: High School, SAT Prep, College geometry.

Let the angle AOB be the given rectilinear angle. It is the required to bisect it. Post a comment.

Book I, Proposition 9, To bisect an angle


The Elements: Books I-XIII

Euclid's Elements is the oldest mathematical and geometric treatise consisting of 13 books written by Euclid in Alexandria c. 300 BC. It is a collection of definitions, postulates, axioms, 467 propositions (theorems and constructions), and mathematical proofs of the propositions.

  Recent Additions