s measured in radians, then the distance between A and B is given by d(A,B) = R a,where R is the radius of the sphere.Appendix 1-4:Appendix 2-1:Appendix 2-2:Appendix 2-3:Appendix 2-4:If two lines are parallel to a third line, then the two lines are parallel to each other. This is a theorem in Euclidean Geometry, yet in Hyperbolic Geometry it is proved false by the above counter example (Both BA and BC are parallel to DE, yet BA is not parallel to BC). However, you may not be convinced that BA and DE are parallel....
