Which of the following is not a characteristic of non-euclidean geometry?

a.
space is saddle-curved.
b.
the parallel postulate is false.
c
there are no straight lines.

For the answer to the question above, the choice is incomplete. The choices are all correct so there's no wrong answer or there's no answer to the question. When it comes to angles In non-Euclidean geometry, the sum of the angles in a triangle is always less than 180. If it's equal to 180 then it's Euclidean if it's greater than 180, it is elliptic.