Source : Webster's Revised Unabridged Dictionary (1913)

Triangulate \Tri*an"gu*late\, v. t. [imp. & p. p.
   {Triangulated}; p. pr. & vb. n. {Triangulating}.]
   1. To divide into triangles; specifically, to survey by means
      of a series of triangles properly laid down and measured.

   2. To make triangular, or three-cornered.

Source : WordNet®

triangulate
     adj : composed of or marked with triangles
     v 1: divide into triangles or give a triangular form to;
          "triangulate the piece of cardboard"
     2: measure by using trigonometry; "triangulate the angle"
     3: survey by triangulation; "The land surveyor worked by
        triangulating the plot"