Non-Euclidian Geometry Explained [video]
youtu.be
youtu.be
This video compares and contrasts three different types of Geometries:
o Spherical Geometry
o Euclidian Geometry (the one we all know)
o Hyperbolic Geometry
With the wonderful property that
Spherical Geometry is sort of the opposite of Hyperbolic Geometry...
(Note to self, have to do more research on this!), i.e.,
Circumference of a circle:
Spherical: 2 x pi x sin(r)
Euclidian: 2 x pi x r
Hyperbolic: 2 x pi x sinh(r)