Geometry of the Universe

There are three possibilities describing the Universe's geometry. If the constant curvature (how much the average curve of a shape is) of the Universe is zero, the Universe is flat. In simpler terms, you could go indefinitely in one direction, you would never return to where you were. If the curvature is more than zero, the surface of the universe is a finite sphere. If it is less than zero, the surface of the Universe is hyperbolic (or a place where more than one line can be drawn through a point that is parallel to a given line). These three theories of the shape of the Universe describe the three types of geometry: Euclidian, Spherical, and Hyperbolic.  Knowing the Universe's geometry is critical for finding out when, how, or if the Universe is going to end.