Directed distances along straight lines are vectors that give the distance and direction between a starting point and an ending point. A directed distance of a point "C" from point "A" in the direction of "B" on a line "AB" in a Euclidean vector space is the distance from "A" to "C" if "C" falls on the ray "AB", but is the negative of that distance if "C" falls on the ray "BA" (i.e., if "C" is not on the same side of "A" as "B" is). For example, the directed distance from the New York City Main Library flag pole to the Statue of Liberty flag pole has: