Euclid's Fourteenth Proposition in the Poincaré Disk
- Author:
- soundmanbrad
Euclid's Fourteenth Proposition in the Poincaré Disk. - http://aleph0.clarku.edu/~djoyce/java/elements/bookI/propI14.html
If with any straight line, and at a point on it, two straight lines not lying on the same side make the sum of the adjacent angles equal to two right angles, then the two straight lines are in a straight line with one another.
With any straight line AB, and at the point B on it, let the two straight lines BC and BD not lying on the same side make the sum of the adjacent angles ABC and ABD equal to two right angles.
I say that BD is in a straight line with CB.