Noun
the geometry of 2-dimensional figures
Source: WordNetAffine transformation in plane geometry A simple affine transformation on the real plane Effect of applying various 2D affine transformation matrices on a unit square. Source: Internet
Euclidean geometry Euclid's construction for proof of the triangle inequality for plane geometry. Source: Internet
The axioms unify both the plane geometry and solid geometry of Euclid in a single system. Source: Internet
There are 13 total books in the Elements: Books I–IV and VI discuss plane geometry. Source: Internet