| 释义 |
elliptic plane Spherical geometry (see spherical trigonometry), with the great circles replacing lines, is not a type of non-Euclidean geometry; this is because two ‘lines' do not meet in a single point but rather in antipodal points. If, instead, antipodal points of the sphere are identified then we create the elliptic plane, which is a non-Euclidean geometry where each line has no parallels. The elliptic plane has the topology of the real projective plane.
|