what is one way that a line is the same as a ray
Line (geometry) When a geometry is described by a set of axioms, the notion of a line is usually left undefined (a so-called primitive object). The properties of lines are then determined by the axioms which refer to them. One advantage to this approach is the flexibility it gives to users of the geometry. Thus in differential geometry a line may be interpreted as a geodesic (shortest path between points), while in some projective geometries a line is a 2-dimensional vector space (all linear combinations of two independent vectors). This flexibility also extends beyond mathematics and, for example, permits physicists to think of the path of a light ray as being a line.
Yellow line (road marking) Some parts of the US use a doubled set of double yellow lines to demarcate a painted median strip, which vehicles are not permitted to cross. This differs from a single set of double yellow lines, which may be crossed in certain circumstances.[14]