import Common.Geometry.Point /-! # Common.Geometry.Line A representation of a line in the two-dimensional Cartesian plane. -/ namespace Geometry /-- A `Line` is represented in vector form (not to be confused with `Vector`). It is completely characterized by a point `P` on the line in question and a direction vector `dir` parallel to the line. Such a line is represented by equation ``` \vec{r} = \vec{OP} + t\vec{d}, ``` where `O` denotes the origin and `t ∈ ℝ`. -/ structure Line where p : Point dir : ℝ × ℝ end Geometry