Almost Triangulation : why you need at least two measures to guess where you
are ...
4 landmarks solution
3 landmarks solution
Why we should use the 3 landmarks solution
Why we should use the 4 landmarks solution
Always use landmarks as away as possible from you
Triangulation : A method of fixing an unknown point (for example in navigation)
by making it a vertex of a triangle whose other vertices and angles are known
(Collins Dictionary of Mathematics).