Euclidean plane geometry

One can't dissect a square into an odd number of triangles of equal area

geometric shape in two-dimensional space

geometric curve associated with a quadrangle

a set of orthonormal bases, where each vector of a given basis has the same overlap with all the vectors of other bases

line segment defined from an angle and a point: given a point P that lies inside an angle with edges d and e, the shortest line segment that passes through P and has its endpoints on d and e

geometry; how many 3-point lines can n points form