Abstract: Method and system for rapid triangulation of a region into an array of triangles that can be used for a GIS triangulation. A dataset S of three or more distinct points is set down, and an array including a sequence of triangles is constructed, using these points as vertices. A triangle is removed from the array if at least a triangle included angle is greater than a selected threshold angle value (such as 90.degree.) or if the ratio of triangle height to triangle width is too large. A first triangle is replaced in the array by one or more other triangles if a first triangle included angle is less than an included angle for a second triangle, formed by replacing the first triangle included angle vertex by another point in the dataset S. The new method provides an acceptable triangulation, with computation time equal to about 40 percent of the time required for a Delaunay triangulation using the same dataset S. The dataset and/or the array of triangles can be displayed and manipulated.