Determine the coordinates of an unknown point M (impossible to occupy) visible from two (2) previously surveyed reference stations A, B of a control baseline, only by observing angles α and β subtended by lines of sight from stations A and B to the intersected point M. Intersection technique is commonly implemented when the unknown point to be observed is inaccessible during a survey.
Calculate the maximum offset value ΔΖmax of an extrusion or intrusion detail from a reference plane (mainly flat object) so that the maximum error on the image plane due to radial shift does not exceed a certain limit Δρmax. (optical axis perpendicular to object plane)
Calculate the surface area of a simple (non-self-intersecting) n sides polygonal shape with known Cartesian coordinates in the plane for all of its vertices. The main concept of the method is to divide the main polygon in n trapezoids
and to cross-multiply corresponding coordinates to find the area enclosing the polygon (green trapezoids), and subtract from it the surrounding trapezoids (red) to find the area
of the polygon within. It is also called the shoelace formula because of the constant cross-multiplying for the coordinates making up the polygon, like tying shoelaces. Mainly applicable in topography.