Geometry/Neutral Geometry/Axioms of Betweenness
< Geometry | Neutral Geometry
Axioms of Betweenness edit
Betweenness Axiom 1 edit
If A*B*C, then A,B, and C are three distinct points all lying on the same line, and C*B*A.
Explanation edit
Betweenness Axiom 2 edit
Given any two distinct points B and D, there exist points A,C, and E lying on line BD (needs format with LaTex) such that A*B*D, B*C*D, and B*D*E.
Explanation edit
suppose that in a certain metric geometry the following distance relationship hold: AB= 2 AD=BD=CD=3 BC=4 AC=6
Betweenness Axiom 3 edit
If A, B, and C are three distinct points lying on the same line, then one and only one of the points is between the other two.
Explanation edit
Betweenness Axiom 4 edit
For every line l and for any three points A, B, and C not lying on l:
- (i) If A and B are on the same side of l and if B and C are on the same side of l, then A and C are on the same side of l.
- (ii) If A and B are on opposite sides of l and if B and C are on opposite sides of l, then A and C are on the same side of l.
Corollary edit
- (iii) If A and B are on opposite sides of l and if B and C are on the same side of l, then A and C are on opposite sides of l.