In particular, the distance from a point x ∈ R to a hyperplane H where x / ∈ H , is given by the length of the perpendicular line segment from x to H . If two hyperplanes H1, H2 are parallel, their normal vectors are multiples of each other, so we can take a single normal vector u and write H1 = {x : (x, u) = α1} and H2 = {x : (x, u) = α2}. Take any x ∈ H1 . Then d(x,H2) is given by the perpend...