Choose a background or upload your own photo, then download a shareable quote image.
Choose a background or upload your own photo, then download a shareable quote image.
Proofs of the Euclidean [parallel] postulate can be developed to such an extent that apparently a mere trifle remains. But a careful analysis shows that in this seeming trifle lies the crux of the matter; usually it contains either the proposition that is being proved or a postulate equivalent to it.