Real Dictionary

triangulation in American English
the process of determining the distance between points on the earth's surface, or the relative positions of points, by dividing up a large area into a series of connected triangles, measuring a base line between two points, and then locating a third point
noun: a technique for establishing the distance between any two points, or the relative position of two or more points, by using such points as vertices of a triangle or series of triangles, such that each triangle has a side of known or measurable length (base

triangulation in British English
noun: a method of surveying in which an area is divided into triangles, one side (the base line) and all angles of which are measured and the lengths of the other lines calculated trigonometrically