11. The Euclidean plane is not hyperbolic, for example because of the existence of homotheties. 12. One can consider similar minimal surface problems on other quadrilaterals in the Euclidean plane . 13. Projectivization of the Euclidean plane produced the real projective plane. 14. By contrast, the group of conformal transformations of the compactified Euclidean plane is only 6-dimensional. 15. There are 151 4-uniform tilings of the Euclidean plane . 16. Diffeomorphic to some open set in, the Euclidean plane . 17. There are 332 5-uniform tilings of the Euclidean plane . 18. Examples include the polar coordinate system on Euclidean plane , the second important plane coordinate system. 19. The two-dimensional grid is not hyperbolic ( it is quasi-isometric to the Euclidean plane ). 20. Elliptic geometry has a variety of properties that differ from those of classical Euclidean plane geometry.
