Triangulation finds the coordinates and distance to a point by:

• Creating triangles with other known points
• Calculating the length of the triangle’s sides and its angles
• Using known ratios of angles and the law of sines to compute the coordinates

It’s basic geometry on a big scale. GPS draws triangles with 11,000 satellites orbiting  in space and ground stations here on earth to calculate the precise altitude, longitude, and latitude.

Mathematically, GPS requires four satellites to determine exact position. Three satellites suffice with a second GPS base station or other filters.

Surveying involves the solutions of large meshes of triangles. Complex systems of simultaneous equations generate site data.