Dictionary

In a stricter sense: Euclidean geometry is the standard geometry taught in school (synonym: plane geometry). In a more general sense: Euclidean geometry is the generalization of this geometry to include three-dimensional space and even higher-dimensional spaces. The three-dimensional space we are used to in everyday life is called Euclidean space. Quite generally, spaces with three or another number of dimensions and Euclidean geometry are called flat.