It is a consequence of Euclids's parallel postulate.
first five postulate
need a simple explanation of Euclids theory.
Because it will eventually complete a Circle, like the dachshund that met its end going round a lamp-post.
eetrgrv
euclids elements
geometry
geometry
Euclidean geometry is the study of points, lines, planes, and other geometric figures. The most prolonged argument over time has been that of the parallel postulate which states: there can only be one line that contains a given point and is parallel to another line.
compositions
euclids elements
Pythagoras